I can't handbrush anything without making a mess, but that certainly doesn't mean much. I've seen too many immaculate paint jobs done with nothing but a brush.
Two things I do know about handbrushing:
1) You absolutely have to get the paint so it will flow properly or you get uneven coverage.
2) When using acrylics you absolutely have to slow down the drying time or you'll get ridges and rough coverage. The paint must have time to level out before it starts to dry, and acrylics don't give themselves enough time.
With Tamiya acrylics the best way to dd both of those things is to use their brand of primer. It thins the paint so it can flow and it also has some retarder in it to slow down the drying time. I don't know how their primer works with other brands of acrylic, but you can thin them with various substances. Acrylic retarder is available at most art supply stores and a drop or two will dramatically slow down the drying time.