The pneumatic gain of the wastegate, which is dependent on the ratio of valve size to dome diaphragm size, is as much or more important than the type of controller.
If the gate has a large diaphragm area compared to valve area, the spring and dome will have much more boost stability than a lesser ratio.
The minimum gate valve size depends heavily on the turbine flow.
Because I ran a T4 1.25 A/R with a 96mm turbine inducer I could use a single RG-45 gate to dial boost anywhere from 13 or so pounds up to 30 psi. Just applying fixed CO2 on top of the dome allowed me to dial boost within one or two pounds of target.
When I changed to a bigger Turbosmart gate that has a smaller dome diaphragm, my control went to pieces. I went back to the RG-45.
Now I changed to a TiAL V-band housing 102 mm inducer turbine. The turbo drive to boost pressure ratio dropped from 2.2:1 at high boost down to 1.7:1 or less. Because turbine flow is so much better across all boost ranges and my newer compressor is so good, I can no longer pull high RPM boost below 20 psi even with zero dome (a 10 lb spring).
I've just added a second RG-45 gate in an attempt to get the system back in control.
I have to get the gate system to be able to dump off enough exhaust to slow the compressor down. Since I'm adding a second gate like the first, the system pneumatic gain (ratio of diaphragm area to gate vlave area) will not change. This should get the turbo back under control.
The important point in all this is the basic gate has to be of good design, which means a large diaphragm area to valve area, or control will be poor no matter what system you use.
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89 LX. 363, single turbo, Super Vic EFI, TFS high port heads by TEA, solid roller, glide. Holley HP EFI. (exact combo varies)