I use to use omni when I wanted to use a lower line paint, but after having a few coverage problems started using limco when using a lower line. Coverage to me seems to be just a little bit better then the omni, and even had it match good enough for a blend on two jobs. These were base clear. I did paint one of my cars with omni single stage urethane though about 5 years ago, and it covered decent and has been holding up pretty well. Think it cost about 100 bucks for the gallon and the hardener needed. I never used kirker. There is quite a few discussions on kirker at hotrodders.com, do a search for kirker on there, but everytime the name kirker was brought up a argueing match began. I have a feeling the guy causing the most problems was associated with kirker in someway, either being a jobber or involved some other way with them. Not positive, but he has been banned from the site anyways. I have used the marhyde clear they also sell through smart shoppers quite a few times, and I like it. It is thicker then most lower priced clears and looks pretty good. It sort of always looks like it has a yellowish tint to it when you pour it out, but haven't noticed a yellowish tint when sprayed or changing the color of the base. There are several decent lower priced paints that will get the job done, but the cheaper paints aren't always a bargain if you end up using twice as much paint to get the car covered, more reducer used, more chance of solvent build up if you don't allow enough time between all the coats, and more time spent painting. Don't get me wrong, with the price of paint today, I use a lower line a lot of times, but the better lines should make the painting a little easier on you, and a better line that has been around for awhile you should last many years. Its also nice to get paint that is available locally if you happen to run into a problem and you need to get something today cause you are in the middle of spraying.