I have used Rustoleum and Krylon primers a lot. Krylon is my go to. Now, one qualification is that these are full bodied primers and go on pretty thick. This is great for use over seams, scratches, etc., but some folks object to the fact that they can soften detail. So kits with really fine detail may call for use of a model paint primer, but other than that, I really like Krylon primers, but will use Rustoleum in a pinch if local stores are out of Krylon. BTW, I have found my local Walmart carries Krylon at the cheapest price of anyplace I know of.