largest benefit is the total lack of thorn-type punctures, so long as you use sealant.
it is/can be a bit of a faff. minimum of a good high flow track pump for inflation IME, compressors can be very useful, or CO2 pumps (cheaper if you get canisters from BB/paintball gun places). once you have done a few and got the knack the faff seems a lot less troublesome. changing tyres take longer.
you should still carry a tube (IMO) since damaged tyres will otherwise end a ride. that said anything that damages a tyre enough would likely have punctured a tube, so you're not worse off. you can run lower pressures and grip/feel does seem to be better even at similar pressures.
some have had issues with ghetto setups burping/rolling off rims. i've been issue free for nearly a year/ ~1500 miles.
it's all about the puncture-free goodness though for me.