Ghetto tubeless is heavier than a decent tube and rim, but you can run lower pressures, never pinch flat, and ignore thorns. Also some people reckon it makes the tyres more supple but me, i don't know, can't tell the difference. I don't think it's better or worse mind, i think it's just different. I'm not that bothered by punctures so I went back to tubes on my standard rims, for me they're better.
A standard tyre on an UST rim should be lighter than a sensible tube, and gets all those advantages, so I think it is objectively better. Sealant definately needed though. These I'll leave tubeless.
And full on UST tyre + UST rim doesn't need sealant, but unless you never ride anywhere where there's anything sharp you'll want it anyway- the tyres tend to be tougher than non-UST tyres (that's why they're heavy) but they'll still puncture on thorns etc. Not for me, by either method, don't want the weight but again, that's a personal call.