After hours of testing various acrylic paints in our dry high desert environment, I can, humbly, offer the following advice:
1. Once you understand how to thin Mission Models Paint (MMP), MMP sprays the best with least overspray, and with very minimal to no tip dry. MMP also offers a nice selection of armor colors. Their Dunkelgelb Ral 7028 (MMP-011) is a real winner and looks accurate to me. I also like their olive drab selection. I use 1 drop of their thinner, 1 drop of their Poly, to ten drops of their paint (before learning to use their paints, I over-thinned them and that created all sorts of problems). I also use a 10:1 mix of their thinner and Poly but I find that using MMP thinning recommendations is the way to go. I also had success using airbrush medium (Golden) but I suggest that you stick with MMP products and their thinning recommendations before experimenting with other thinners/reducers.
2. Hataka Red Line - these are a close second to MMP. Spray great, great coverage, minimal to no tip dry and nice satin finish. I purchase directly from Hataka (Poland). Hataka uses DHL and delivery is fast to USA, and buying higher quantities can lessen the unit cost impact associated with DHL shipping. Absent Hataka acrylic thinner, Hataka recommends Vallejo Airbrush Thinner. I combine 10 drops of paint with 5 drops Vallejo Thinner and 5 drops of Vallejo Flow Improver - sprays great at 15-18 psi. For fine lines and Camo, I increase thinner to 10 drops and reduce flow improver to 3 drops while decreasing pressure to 8-10 psi. Hataka's Ral colors are very accurate; particularly, Ral 7028 and Ral 7028 Augsabe 1944.
3. Vallejo Model Air - good choice but too much tip dry unless you use an excessive amount of flow improver; which slows drying times and makes the paint overly translucent. I mainly use them for base colors. I'll reach for MMP or Hataka when spraying fine lines and Camo with acrylics.
4. AK Gen3 - disappointed. Vallejo Model Air is superior in my opinion.