I think this topic was just discussed a few days ago since there was another thread on this (and many times before).
In reality, 2ZZ-GE and 1ZZ-FE engines have only 1.8 liter displacement in common. Just about everything else is different.
XRS has been discontinued so you would not find a brand new one.
As a previous Corolla S owner turned XRS owner, it was definitely worth getting an XRS for the price since I cared for the extra sportiness, handling, 6 speed stick shift as well as the 170 HP at the cost of some comfort, gas mileage and premium gas.
Maybe this detailed review will be helpful for you:
http://www.motortrend.com/roadtests/...car_comparison