I don't have any experience with Masterbox kits, so I won't comment on those. Though I have built a Mini-Art kit once in a while. Basically their an Eastern Eurpoean brand meaning their moldings are just not up to par with Tamiya and Dragon kits. I'm not saying the kits are bad, it's just you need more TLC(tender loving care) to really make these kit's *pop* with detail. Since they may have more seams, ejector pin marks, and flash. They can be turned into stunning builds, but long story short you'll need to spend a bit more time on them, nevertheless it can pay off.
Just don't expect a Tamiya type kit where you can simply shake the box and the kit will fall together with ease. Expect to do abit more work.