Welcome to the forum. I have some experiences with the different engine types (almost bought the Corolla XRS but got a much better deal with my Matrix XRS). I currently own an 8th gen Corolla with the 1ZZFE and a 9th Corolla/Matrix (1st gen Matrix) with the 2ZZGE. Both have be extremely reliable, good on gas, and relatively cheap to keep up.
As for reliability - as long as you stay on top of the maintenance and resist the temptation to hit "lift" until the car is fully broken in (in your case, I hope the original owner did this) you shouldn't see too much differences between the XRS and other trim levels. Shifter is a bit weird compared to the 5 speeds and clutch takeup is a little different - but you should get used to them pretty quickly.
Things that I liked about the 2ZZGE over the 1ZZFE counterparts:
- decent low end power with nice jump at the switch over point to the big cam (addictive pull at the lift point).
- got better mileage the harder I drove it (haven't figured that one out yet).
- lots of hidden potential if you are a motor head and like to mess with cars
- disc brakes all around (much easier than messing with drums brakes, much better initial bite and smoother modulation of brakes)
Things that I didn't like:
- goes through gas faster
- recommends premium (91 octane or higher) fuel
- Dr. Jekyll and Mr. Hyde personality got old
- got to get it up in the revs before it starts making power (highway cruise on the Corolla has RPMs around 2000, same speed with the XRS is around 3000 and some change)
Most of the problems with the engines have been worked out before they got to the Corolla XRS. The biggest problem of the lack of torque has been addressed with the Corolla XRS tuning (more torque at low revs by sacrificing top end revs).