My dad bought an '85 XJ new with the 2.5L, 3.73 gears, manual trans, and slightly larger optional tires. At the time the 4.0 was not an option, just the GM 2.8 V6 which he definitely wasn't going to buy. My dad has said that he wished the 4.0 was available at the time because he would have bought that instead. My dad usually goes for the smallest engine he can get and thinks his first gen Civic Hybrid has plenty of power, so that's saying something. Granted, this Jeep did have a 1 barrel carb, so it wasn't as powerful as later versions. It was reliable, except for an unusual appetite for water pumps.
A lot of my friends have bought Wrangers, but many were ragged out and had been modified at some point in their life, so that by itself introduces some issues. Seems like the 2.5 is fine with stock tires, but anything over 30" or so will often require a regear with that engine. Soft tops are much louder than hard tops, so keep that in mind if you're going to be doing commuting or highway driving in it. The '97+ interior was definitely an improvement, but it's still very spartan.
The only major mechanical failure I've heard of a Wranger having was when one of my friends had the t-case literally explode on his 2.5 Wrangler. Not sure what caused that, but it had about 120K or so miles at the time and it just grenaded as he was making a turn on a paved city road. The Jeep did have larger than stock tires (33" IIRC).