good question . from what i have seen people either love or hate them. i never tried one myself. i do know of a guy who used one of those cheap barrels from midway --swenson i think that are like a roto. i got to shoot it and it functioned fine but to me it seems to shoot low--a while back midway had um on sale for like $29 for the 5" 45acp -- i have thought about trying one in 40-- but if it is a turkey i hate to have wasted $54 ---
personally i would say get a colt barrel or a storm lake drop in. sure their going to cost you at least twice as much as the roto but as expensive as ammo is you can waste enough ammo trying to sort out a poor barrel to eat any money you saved buying the cheap barrel real quick.
i recently got a 6" storm lake -- it is a very impressive barrel-- and 100% drop fit in the para slide too--
rule of thumb --if the pistol is sort of a klunker --the cheap barrel might be OK --but if it is a very nice 1911 i would get a storm lake, colt, kart ect for it.