If you're willing to venture outside of acrylics, given Alclad's new stuff a look-see. Just used their clear matte for the first time last night and LOVED it. I've had all kinds of problems with flats before (including Pollyscale spitting white flecks all over a Dauntless). This is the first product I've used that's worked flawlessly. The also make a gloss, semi-gloss, and flat. The matte is more of a flat with a very subtle sheen to it...they're all mineral spirit based so cleanup's pretty easy.
They also make a Future substitute that's supposed to be amazing. I haven't tried it yet, but I've got a bottle on the paint rack just waiting for an excuse!
On the Bench: 1/32 Trumpeter P-47 | 1/32 Hasegawa Bf 109G | 1/144 Eduard MiG-21MF x2
On Deck: 1/350 HMS Dreadnought
Blog/Completed Builds: doogsmodels.com