What I have noticed, is that the silicone pillow seems to be keeping it's shape longer, and, it's not turning yellow like the F20's did.
I've been cleaning both the exact same way. Clorox anti-bacterial wipes. The AirFit F30 (for me) is really working out well. Very comfy and even though I'm a side sleeper, I can bury my face in my pillow w/o much worry about my mask getting moved around and then leaking. I do tend to wear it a bit on the tight side, and the leaks are minimal.
It's easy to adjust as well. Usually just a tug on the portion that's under my lower lip, and all is good again.
I'm shooting for six months of use with my F30. I don't think that's impossible. If I saw four months of use with an F20, I felt that was good. Usually, the yellowing kind of turned me off and I swapped it out for a new pillow.
It might sound kind of weird, but I don't throw the used ones (pillows) away, not as of yet. I clean them well and put them in a zip-lock bag and store them. Not sure why, I just do.