So far they work great. We sell them, or a model similar(?) and have had zero problems with them. At least that I’m aware of.
Certainly no leaks like the standard brass models offer. Due to not having that same delay valve feature.
Interesting thing is that Wilwood now also makes one just like those brass ones.
I haven’t seen one yet, but have been curious if they are of any higher quality.
Don’t plan on connecting stock lines do it without adapters. The fitting sizes of aftermarket vs stock are all different. Though adapting has not been much of an issue up to this point.
Since it sounds like you already have aftermarket units in place however, maybe all the adapting has already been done?
During this time you might also consider trying to fix one of your old leaky ones.
Do you still have them, or did you return them all?
If you still have one laying around, pull that little valve out and check the sealing surfaces for any debris or damage.
Clean it up if you can and reinstall the valve and tighten it down really good to make sure that it’s sealing.
Who knows, you might just have one that works after all!