I've owned both. My first gen was a 5 spd and tons of fun offroad, but had the 4.1 gears so struggled at highway speeds and got terrible gas mileage and was just getting tired. Dead reliable after you fix the recalled fuel sending unit (left me stranded at a ski resort once, but that's it).
I bought the 2nd gen for more of everything essentially. More power, more room, etc. I like it better than the first gen since it is more refined and is a great platform. If I was going to be rock crawling, I'd choose the first gen, but since I'm more into the overland and adventure stuff where I'm not going to be boulder bashing that much, the second gen is a better option in my opinion. But both can do either well when built to your style of wheeling.