I just got mine recently, so I'm not an expert. But one piece of advice, is to make sure you order alternative condoms when you buy it. The ones that come with it are not good. I thought mine was maybe broken or something, but I was just losing suction because the sleeve is not great. I'd also suggest using the large bell right from the start. If you're a lot girthier than average, you might want to order the XL bell as well. I messed around with the medium bell, and I can't get it to stick on. I can't even figure out what the small bell is possibly used for.
I've seen some people have bought super cheap sleeves and been happy with them. I just went ahead and bought the really expensive ones to be on the safe side(I didn't want too much time to pass, waiting around a month on some shipment from Asia). They were only about 10% the cost of the PF, so not a huge deal wither way.
Anyway, it's a lot better than the old style of stretcher. I could never keep those things on. Apparently some people can combine a PF with something like an [words=https://shop.mattersofsize.com/products/sizegenetics-penis-extender]SG[/words], though I haven't attempted this.