i don't want this thread to morph into i am a better painter than you.

just don't blanket knock a quality product that failed when it probably wasn't used properly a few times.

the problems posted about omni being a thinned out product are probably correct on older cars. i don't use omni base coat much so i can't testify to how well it works. also i don't mix my own paint, the owner want it that way. but i have been told when PPG converts some single stage colors to base coat they basicly mix a single stage color with single stage clear and binders. then add 50% base coat clear to the mix to get the base coat formula. basicly giving you 50% less tints per can of paint. this is why it's seems thinned out with no coverage.

i haven't looked at the paint job failures so i don't know exactly what actually happened. but my best guess on what happened is this. because the base coat was thinned out with poor coverage it was probably sprayed on heavy and wet. when this is done the metallic was blotchy with lots of tiger stripes. to correct this color was lightly sprayed on the even out the metallic over the top of wet base coat. when you do this the lightly sprayed color won't bite into the color under it. base coat should always be sprayed on medium wet, never with a dry spray. you should try to avoid spraying it on heavy and wet. spray clear coat on top of the dusted base coat and it will fall of like described.
i have seen this many times with DBC base coat. omni base coat is just like DBC.
but when i do use it i add the DBC base coat activator to the omni base, i have it on the shelf so i use it. i don't spray onmi base much so i don't know if this is available in the omni line. when you add activator to base it allows the chemicals to cross link faster than without using it. when this happens it will give you a better more durable paint job.

when i spray omni clear coat i also add a reducer to get it to lay down better and when i bake it it doesn't die back as much as without reducer. i mix it 4 parts clear 1 part reducer 2 parts catalyst, then add 1 ounce of enhancer per spray able quart to speed up the dry and cure time of the clear. i do know that enhancer is available in the omni line, but i use the product made for 2021 because it's on the shelf.

there is nothing wrong with omni products when used correctly. i used them on my road runner 15 years ago. from etch prime to the clear coat. it still looks as good as the day it left the spray booth.
the one thing to keep in mind is it isn't as durable as a job cleared with 2021 clear coat. it will chip much easier.