A lot of the "fine tuning" that can be done to the TC's is a matter of opinion anyway. If a barrel/cartridge shoots well, I see no need to fool with it. However, I have a barrel that doesn't shoot well, so I figured "what the heck" and spent a few dollars for some tune up parts. I can't say that the accuracy was vastly improved, just a bit maybe.
The oversized hinge pin, headspacing shims, and heavy locking springs make my G2 carbine lock up like a bank vault! One thing that always bothered me was the way the barrel clunked back and forth with the factory hinge pin. With the oversized pin, the clunking back and forth are gone. Can't say that it helps with accuracy, but it makes ME feel better!