OP like >>3751043
says, even LF forums may not give you a a good idea about the lens. LF boomers can be the ultimate pixel peepers who are all about testing and forget to take interesting photos.
If you are looking at a local shop, find out if you can test the lens for a weekend. Some lenses can vary quite a bit from example to example within the same model. The condition of the shutter is another factor, you could end up wit ha lens that needs a $50-$300 CLA before you can use it. If you are buying online make sure you are buying from a reputable seller, and know that if you find a bargain you are rolling the dice on what you get.