This subject seems to bring positive and negative responses on other forums (usually negative). I never use that stuff myself.
http://www.modelcarsmag.com/forums/topic/181168-rust-oleum-paint/
http://www.modelcarsmag.com/forums/topic/178173-rustoleum-paints-are-terrible/
Lots of good and some conflicting info there Peteski...
It's discouraging to read that some guys have been having issues with Tamiya spray primer. Apparently the formula was changed at some point. I'm glad the stuff I stockpiled seems to work OK, at least on 3D printed parts and the miniature war gaming stuff my younger two boys paint with it.
One of the more interesting bits of info was from a guy that thins an enamel with a small amount of lacquer thinner and gets really great results from it.
It's also good to read that I was not alone when having issues with Rustoleum primer being tacky for days after spraying.
A side note... Not sure if I read it here, but someone, on some forum or list I'm on suggested using Napa brand flat grey primer. Said it worked great, as good as or better than Tamiya primer, though I don't recall any more details. Certainly cheaper/a better value if it works just as well.
Edit: Apparently the Napa primer referenced above is part of the Duplicolor brand, which a few of the guys in the threads Peteski provided swear by.
JB