Jonathan, my 1989 Trane is a 12 SEER, which was top of the line then IIRC. You can do better now, of course, but it isn't too bad.
As for the reliability of the compressors, the supposed reason for less longevity is that Trane transferred production to Mexico. Not sure. Maybe there were just some glitches, but I've known, unfortunately, two people who've had failures with the Mexican-made units. The Trane compressor was the old GE Weathertron design, which they bought when GE unloaded their home heating business. For some reason, this was reputedly the most rugged compressor design ever. I've certainly had no problems; it's never even needed a recharge. But it's helpful to know they've been reliable for you!
Jerrod, I can't address your local gas utility issue, but generally there are a lot of issues now that will certainly put heavy pressure on electric rates -- new EPA regulations on mercury, particulate matter, and carbon will make any coal-fired generation much more expensive, and many states have mandates on renewable energy that also tend to be costly in the aggregate (though they may benefit some people through feed-in tariffs). Meanwhile, Pennsylvania is sitting on one of the largest gas fields in the world and there is a flood of new gas supplies in your area. My inclination would be to go with gas.
