I've had a share of horror stories both within the RPGA and outside of it.
I've been in extremely bad RPGA Classic modules, and terrible RPGA Living Greyhawk / Living City modules. On the other hand, I've been in some real gems. My experience with other games is exactly the same.
I've played in an LG scenario where a widget we never heard anything about beforehand caused a will save no one could make without a nat-20. Failure resulted in an insane need to kill the person with the widget and take it for yourself.
I've played in a Shadowrun Classic scenario where the Street Samurai had no Cyberware listed, despite his Essence of 0.1, and all the other characters had errors of similar magnitude. Another Classic allowed the PCs to play second fiddle to NPCs; we couldn't tie our shoes without help.
But, then, I've played an LG scenario where the players had so much fun, we decided to extend the (role-play intensive) scenario for 5 more hours rather than go eat or go to our next slot. I've been in a different group that was so much fun that I can still remember most of the characters' names today.
I've played a pair of Classic events that catered to my tastes in gaming almost exactly. Where I actually role-played better than I had realized I could manage. "Binding Arbitration" was so much fun that I have since run it and re-played it more than a couple times.
Does it surprise anyone that I've had similarly good and bad experiences outside the RPGA? A non-comedy Sci-Fi game in which the characters were making rolls for sexual performance and to determine if they caught an STD? A highlander game in which the PCs were the poor mortals caught in the clash of the uber-statted immortal NPCs, Connor and Kurgan? Demo games that so toroughly sold me on the product that I bought copies for everyone in my game group? Games so well done that I look for the names of the GM on the schedule of every convention I go to?
The players are a mixed bunch, too. I won't belabor this with further examples.
So here's my point: the games and the gamers vary from place to place and group to group. If the RPGAers at your local con are consistently people you don't want to play with, cool. I just wanted to make you aware that the brush you were using was a little too wide. And the experience from a single con is probably not enough to judge everyone in the RPGA... or even everyone who ever DMs for that Con.
By all means, play the odds. If you think it likely that non-RPGA games are more likely to be fun for you, go for it. If you miss out on a good DM or two, it's probably worth it given how many you might otherwise never meet because you were asleep at someone else's table.
Personally, I go out of my way to play with the good gamers, because they're easier to remember than the bad ones. I take recommendations from people I trust, and I've learned to ask questions about the module ahead of time (especially since LG started using modules expressly intended to kill of characters).
... bah, I seem to have lost my point somewhere. Or maybe I made it already, and didn't know when to shut up. Anyway, if you want recommendations for who to play with, there are a fair number of good people on this very board.
Dang. Now I'm going to have to start thinking about how to write a web app for player & DM recommendations. Yeah, like I needed more work...
. . . . . . . -- Eric
PS -- For the record, I have never run a bad game or failed to roleplay well, and I'm the best person to employ in my entire field. Honest.