Valve recommendations?

Hi-
I'm wondering if anyone has a recommendation for brand of shower valve?

I'm in the middle of a bathroom remodel and the American Standard pressure balanced valve I just installed restricts my flow terribly. I've tried removing the pressure balancer and everything is fine without it. I replaced the cartridge with a brand new one. No better. Pressure is fine...40psi. The spec sheet says at 40 psi the average flow from the tub filler should be over 4 gal/min. I get 2.5 from the tub filler with this cartridge. Much less from the shower.

I have a brand new 1" copper main, 3/4" branch line to a 1/2" supply to the fixture. All brand new. I get 7 gal/min without the pressure balancer. So I don't think I have any obstructions that would be hurting my volume. I've flushed the lines too.

I'm desperate at this point. I didn't spend all this time on a gut remodel of an old bathroom to end up with a shower that feels like it's dripping on me. What should I do? Does anybody know if there is just a more reliable brand valve? Should I replace it? Should I continue to look for an obstruction in the line? Do I just need to suck it up and install a pressure booster pump at my main?
Help please!

Previous thread

Previous thread has more background info, so you can see how I'm now thinking I might just have a crappy model of valve.

https://terrylove.com/forums/showthread.php?t=7974

shower

Are you referring to the pressure balancer in the valve or the flow restrictor in the shower head. Pressure balancers typically cannot be removed without seriously compormising the temperature control in the shower.

Yes. I'm referring to the pressure balancer in the valve. It seems that that is the one thing that really restricts the flow. I only removed it to test. I know that short of finding an "illegal" valve on an online aution site or somewhere, I'm not going to get around having an anti-scald type valve. At this point I'm mostly wondering if anyone has had any experience with a particular valve performing better than others. All the reading I've done has kinda led me to believe that all of these types of valves seriously restrict the flow unless you have exceptional pressure (which I don't).

Non-pressure balanced valves are still widely available, because for the most part the codes allow a "repair" meaning replacement of the valve, short of a bathroom "remodel" .

Between a shower flow restrictor in many of the valves ( to make the diverter work ) and the low flow shower heads, you might just as well resign yourself to low flow from the shower. Look for a better head. You should be able to get 5 to 7 GPM from a tub filler, however. Check the manufacturer's websites. They have flow specs for their valves.