Sorry, I got here from Twitter and I have to bite:
1) Your EVO didn't play games faster than your Pre? I assume, then, that your Pre was overclocked, which means it ran hot and sucked the battery dry while trying to play games. I'll take even speed with 20 times the battery life on my EVO any day over that. Not to mention that the overall sluggishness of even an overclocked Pre meant that responsiveness in the game was poor, and then add the fact that you had to play it on a tiny screen.
2) The fact that the Epic doesn't even have 2.2 yet isn't a big a deal for the end users because of speed or battery life or even features, I'll give you that. It's a big deal because of the REASON Samsung hasn't upgraded the Epic yet. Samsung's APIs are so horribly developed on that phone in the first place that it's crushing them to try and upgrade to 2.2 (this comes directly from a Sprint source, which is why they can't get Froyo past Sprint in the first place). They basically wrote them to just barely function properly, while they should have written them PROPERLY. That's especially pathetic for a device that was delayed in launching in the first place several times because of lack of hardware availability. They had time to fix the software, but why would then when it's working... sort of...
3) Another reason the delay sucks is what is mentioned above: ROMs. Sure, you can put 2.2 on yourself, but having an EVO - the phone with the most custom ROMs available right now - I can tell you that even the best AOSP ROM developers can't get their ROMs to match the stability of a Sense ROM because they simply don't have the time and resources and access that HTC's own developers do. Samsung's in-house development team might be sloppy and pathetic, but they have those same resources and you ultimately will always get more stable ROMs based off of their stock kernels than you will from any custom developer out there.
When I first handled an Epic, I was truly stunned at the hardware. I even spent three hours in a training course presented by Samsung reps to learn the great features of the phone, and I thought it was about as perfect as a phone could get. Then the phone launched and people really got to use them, and all the errors started popping up. Device won't sleep because of the terrible design of their DRM manager software. GPS issues with all of their Galaxy S devices (another area their cheap GPS chips and poor software combined to create utter failure). Haptic feedback lag, especially on low-end Samsung devices. Sure, yours might work fine, but that doesn't counter the fact that they're poorly programmed devices.
The first and last Samsung device I would ever purchase is a Nexus S. You get the great Samsung hardware and keep Samsung's god-awful developers away from the software.