There is a vocal group of 2.5L lovers who will likely now post that they "get 30mpg and can easily go 70mph up a mountain"
Only if they have a hurricane force tail wind.
That reminds me of driving back to college to register for my final semester my senior year in my new '65 VW Bug. I had a stiff headwind and those 40 squirrels could only manage 50 MPH (60 MPH zone). A friend and classmate passed me in an older American V-8 and waved. Later coming the other way I now had that stiff tailwind and passed him doing 70 MPH and waved at him.
It may not seem like it but the TJ is actually more aerodynamic (relatively more). The windshield in the TJ has more of a rake, so the full doors and tops from a YJ will not fit on a TJ. Everything fits fine up to the header bar and windshield posts.
Each generation of Jeep (real Jeep) gets a little more refined. The original flat fender is about as refined and a horse and buggy, the CJ is some better, but reflects the 1955 design time frame. Then the YJ followed by the TJ and now JK. I had a '91 soft top and later a '93 hard top then got out of Jeeps in '96. (Boo Hiss time).
When I got into my 2003 TJ on the dealers lot two years ago, I was amazed at the interior comfort and the smoothness of the ride. And this was going to be my occasional driver. If I had seen a similarly clean YJ I doubt I would have given it a second look.
But, if it fits what you want to do, go for it. Keep in mind that unless you really overpay, and you hate it, you won't lose much. Be sure the check the underside for rust, really, really check it. Also if the seller won't give you a CarFax report, pay for one yourself. It will give you an incredible amount of detail not otherwise available. My dealer gives them on all their used vehicles.