Even though I have a 2000 Celica, I don't think my opinion would be biased because I tried to sell this thing to get a 97 Eclipse GSX a couple years ago. smile.gif
For my car, the only issue I've had, and it's a minor one, has been the belt tensioner. I've had mine for a little over 4 years now and has about 78,000 miles on it.
My GT gets 28/32 MPG. So it gets good gas mileage.
As for power, well it depends on what you're comparing. The GTS is rated around 180 BHP, the GT around 120 BHP. I'm not sure what a 97 Eclipse is...especially turbo'd.
I would say, Celica. For the simple fact that it's much more reliable.