Well first, let's go back to my point, because you didn't answer. Would you agree or not, that if Valve playtested their own "final" code before releasing the update, even if it was a couple of KotH rounds - that they would notice the OVERTIME error? Because unless it's related to some obscure server plugins, I don't see how they'd miss it, and as far as I'm aware EVERY server had this problem.
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Okay, you actually go too deep into the detail. But let's go waaaay back if you insist. Let's start with public relations then. Sure, there were no forums, no blog sites - but there were mailing lists for the press (well there still is) and fansites who gave every bit of info to the public. You also could write to just about anyone in the company and would get a reply, long before there was a support wiki or employees dedicated to customer support. I personally had lengthy conversations with Gabe, Erik Johnson, Robin Walker or Jess Cliffe, before they even knew that I was representing a fansite. Sure, now their mailboxes are probably overflowed - not their fault, bear with me. So although there were no official information sources, there were plenty of sources where you could get the official information.
How is it looking now? Official forums, but most of the real information we either get from the interviews (I already mentioned this, Chet Faliszek (sp?) is a funny guy, but he is SO not selling L4D2 to me and no one seems to ask the "evil" questions anymore) or from replies of Valve employees, posted by some random dude on them (valid or not, who knows). I know, it contradicts what I said earlier, that you could get info per mail before, but what's important is - the official forums play no role in it. The answers to these e-mails could have been posted on any other site as well, just as it was done before. This isn't raising a standard in public communications, this is merely keeping up with what every game developer should have in first place.
Official blogs: I love those! But those are hardly a two way street when it comes to communicating. Sure it's a part of PR, but it's not a part of communicating with the community, merely a pinboard for everyone to read, though I have to admit, the blogs are currently the most active source of information we have (not even the "secret" press mailing list has such detail in information, though things are announced there a bit earlier).
Valve messed up a lot, since those earlier days:
- I'm sure you witnessed the problems around the release of HL2? Where Valve lied about the reason for delay, blaming the hacker and what not, the webmaster of planethalflife.com at that time (who did this for years) threw a hissy fit and resigned, because someone from Valve lied to his face or something.
Strangely it was also the time, where Valve was the most verbose. Communicating with about every community site, answering mails within MINUTES, Gabe even registered on our forum for some reason, though he can't speak german.

- How much do you know about Episode 3? The third episode, you know, those thingies which were supposedly faster to make, which is why there is no HL3 yet? Valve never admitted that the episode concept failed apart pretty much after the release of EP1 and though EP2 was much much better, it's not HL3.
- How many employees are posting on the official forums? I counted about 5, there are probably more, but I don't read those forums every day, it's a troll fest. Most of those are in the customer support and technical steam division anyway. There is almost none communication regarding games over the forums.
- What about the price policy in Europe? A lot of people had questions, it is probably the forum thread with the most posts on the steam forums, but there is no, NONE, replys to it from Valve employees. Not even in the sense of "it's not our fault", it just was ignored for months now. Fact is, Steam is not in the least competitive in pricing with most if not all other game sources, be it digital or retail for a long time now.
- I won't start with L4D2, too little is known about the
addon game, but the way Valve presented it was a fricking PR desaster.
- There are unpatched games on Steam, games the developers sent the needed files to MONTHS ago. Nothing happens (according to those developers), there is also no statement as to why those games are unpatched and there is no mention whatsoever that you are buying an outdated version (often to the point of incompability or not able to play multiplayer).
- Their official blog has been silent for months at a time
I never really put stuff together like that and it actually seems like a lot now, I wish I didn't. This are just the major PR problems that I remember from the top of my head.
The quality side of this would take too much space, probably, but let me say that I feel that the quality dropped down (not by a lot) since the release of L4D (admittingly, not entirely Valve's game, so maybe not entirely their fault?), but same goes for TF2, which is getting out of balance more and more.
As a heavy you only had to care about snipers and spies before. Now you can get your ass kicked by about anyone:
- scouts can distrupt your crippled as it is movement with a FAN shot or stun you
- pyro can airblast you
- sniper can shoot you with an arrow without you even seeing him
- spy.. yeah he can still kill you, now also with added kritz to the head for the oh so evasive heavy
- solders and demos don't care much and they has to receive their updates yet
Pretty much every class that got an update already got some kind of a weapon against the poor heavy. The heavy got natasha and a frickin sandvich. The spy is basically begging people to kill him using the dead ringer now, instead of trying and sneaking behind them without being noticed and this is about the only game I know, where killing someone doesn't mean you actually killed him. Scout can stun uber, the thing that is supposed to be a tie breaker, which was weakened by the pyro and the scout update to the point, where it is some kind of a gamble if you actually can manage doing anything or not.
This is of course just my opinion, but I play every class about the same amount of time and Valve has been adding or removing the hard counters for almost every class with every class update, changing fundamental game mechanics sometimes.
Oh and there are no demos anymore, for HL1 they even compiled a set of completely different levels to get the idea across. Sure free weekend was an awesome idea, but not having a demo at the same time (at least post release) is just stupid - speaking of PR again, though not only Valve is making this mistake (because of the piracy apparently).
Now I might sound like a whiney bitch, but I'm not. Let's just say that until now, I bought every game (and preordered them if I could) on release. With L4D2 I'm not so sure. I have several hunderds of hours of TF2 playtime. L4D I only played through every campaign a couple of times and a couple of versus games, that's it. I love the setting, but the execution doesn't catch me in a way TF2 does. So this is the first time, I'm considering not buying a Valve game since... uhm... what, 11 years? (Yeah, I even have Blue Shift

)
P.S. Holy shit, this is a massive wall of text. Sorry, but you asked.
TL;DR: I'm a whiney complainer bitch, who will crumble and buy everything Valve produces anyway.