In my 30+ years of driving, I've driven nothing but used cars (save for one trip!). I can't say that there was any difference between imports and US based vehicles (if that's where you're from).
The first (cough, cough) car I ever drove, regularly, was a Yugo.
First car I ever owned was when I was stationed in Germany. A Volkswagon Scirroco. While I was there, one of my co-workers was transitioning back state-side and needed to sell one of his cars; a BMW 325i. That was my second car. Again, since I was in Germany, technically not imports.
Also while there, a friend of my asked me to go with him to the airport and drive his brand new BMW back to the base. Only new vehicle I've ever driven and what a difference! It was another BMW by the way. A seven series.
Once I got back state-side, I just purchased various US and imports. My old '74 Volkswagon Kampmobile can't really be compared given it's age and condition, but I did purchase an Isuzu Rodeo while in Colorado. It was nice, but nothing special; given the other vehicles I've driven before or since.
In the end, I think it boils down to preference and luck. If you manage to find one that's clean and has a solid history of upkeep, you're probably looking at a vehicle that will keep you happy and moving for some years to come.
-Wolf sends