SunRace freewheels seem reasonably well made and affordable, but quality control varies. I'd buy 'em again, considering the low price.

The 13-25 7-speed MFR30 chromed SunRace freewheel is fine on my Centurion Ironman. Shifts better and runs more smoothly than the original Suntour 13-24 Alpha. I've used it on all three of my bikes over the past couple of years, no problems. I'm looking for the 13-28 version but can't find it on Amazon.

The MFM2A SunRace 7-speed, 14-28, is a bit loose and rattly. I don't have the tool to tighten it up. It's on my errand bike which is mostly used for short rides to haul groceries.

My pet peeve is the Shimano MegaRange freewheel. There's too big a jump to and from the largest cog, which makes for some really awkward shifts on climbs. And the MegaRange is really picky about chains. Anything other than Shimano or KMC "narrow" chains will skip over the teeth under load. There isn't enough clearance between the teeth and spacers to use some chains. No such problems with the SunRace.