Cant wait to build a new ULE mag.. need help

[Spider-TW]

Don't be afraid of the ULT. It is certainly more on the edge than the stock assembly. Most problems with ULT's are that the rest of the gun doesn't work first.
ULT's are best installed when your gun is set-up perfectly with the stock on/off. Installing the ULT at that point typically means it will work perfectly also.
If your gun is maintained well. Then they work just fine.

Most gun issues are related to the gun being dirty, including ULT issues. 90 percent of the time I clean a gun completely, install new rings and it works perfectly.

For sure. I have a very well worn x-valve with ULT (the previous owner ran dirt through it). It is like a very light RT on/off. That's one where I only change an o-ring when I have to, because I don't want it to change the way it works.