They're more comfortable and lighter than self inflators (and you don't ground out a hip laid on your side as happens with thinner/lighter SIMs). Not cheap, but these things pan out over time, and at the end of the day it's something that should improve every night you spend on it. We use ours in chair kits, but a SIM does work better for that.
No punctures to date
(This all reminds me I have a puncture in an old T-Rest to fix... clear arrow of blame pointing to the cat for that, but also highlights another good thing about air-beds compared to SIM which is there are no issues storing them deflated and minimum size between trips.)
Pete.