for the difference in ride I'll deal with an occasional squeak. I have done 2, XJ Cherokees (no, no lift) and an 83 dodge 3/4 ton D 250 in poly and never regretted it. I have poly isolator bushings and leaf spring bushings, as well as poly K frame bushings for my Volare.
At the time I was buying suspension parts for it, being a front end alignment guy, I have always preferred MOOG over anyone else for suspension parts.
And about the time that I bought my front end stuff MOOG came out with a 2nd, "premium" line. Up til this point they had 1 choice for bushings and such. and they still offered that part number. But then they started to offer an "enhanced design" line. They still had the same P/N ball joints and bushings, but now they also offered an alternate "heavy duty" ball joint and an "increased durometer rubber" (harder rubber) for our cars. I ordered the old standby for ball joints and the "enhanced" control arm bushings. They don't look any different from the "regular" bushings--certainly don't look poly-- but I have not gotten my car back together to be able to see what they feel like, and its been too long since I last drove it to remember what it drove like...but they were close in cost to the "regular" ones. supposed to be better, not much more money (the heavier duty BJ's were quite a bit more as I remember)
but for the post-er above that asked about the "cheapest" poly parts, the amount of work to replace a given part, is the same--- IF you only have to do it once... I have always hated re-do's.
I go for "bang for the buck" I don't want to brag about being a cheap a$$ but the most expensive available isn't always the best either. Hang around and see what brands are working for your fellow F M J buddies here and base your choice on that. and then compare prices if you must among those selling the same brand of parts.