ready starting to build the sr6 from zero
Personally i can’t really tell much of a difference in feel so i don’t really bother using it.
Any negative pressure helps with these machines so even a small one-way valve, even if you can’t feel it, will add to the experience by keeping everything in place 
As for the t-valve, it needs to be dialed in and locked on tight to work well. Originally it didn’t seem like it was worth the hassle but I’ve completely changed my mind on it. Downside is that the one I use is coverless and is the loudest part of the machine. Full stroke is also necessary for full effect.
The t-valve certainly makes things tighter but I believe there has to be a script with it in order for it to work properly unless you apply the random setting in xtp. I ended up going with out it because a lot of the scripts I use are moderately fast pace. That being said pairing it up with slow scripts was just 
Don’t do that, should be using A1 if there’s no stript for A0. It’s the automated valve control based on the L0 axis. I think if you put it on random it could be closed on down strokes which isn’t what you want.
Having said that, I’m considering removing mine. For me I don’t think it adds much.