I'm in the same sort of boat.. i've had a lot of tx's in my time but they were nearly all dual stick 27mhz. I've had two trigger grip 27mhz too, none of my previous TX have had any kind of adjustments beyond basic trims - not even dual rate and it's features like EPA, exp, that i want and the reason i'm getting a GT3B. I can't offer any performance information but if it's as good as the GT-2 my buddy has then it's good for anything, i've raced for years and admittedly am a bit of a hack but with my experience i should be able to tell the performance difference between the DX's and EX's and Mx's vs the GT-2/GT3b.. and i can't, really.. the difference is so small I have to look hard for it and more than once i thought i was imagining it.. lol. What i can offer is this:

Don't like the cheap feel? put a tennis racquet grip on the grip of the tx, change the wheel for one you do like, rubber bands or harder springs on the return mechanisms for the wheel and trigger.. and you could put a small sleeve of rigid-ish tube like fuel line or silicon hose over the part of the trigger you push on to get reverse/brake

300-500$ TXs are probably a touch faster and have more features, and are much more adjustable within those features, but if you're just starting to race, you won't notice it unless you're the next multiple time world champion. The main drawback such TXs have over the Flysky radios is the Flysky RX is a few bux whereas the rx for "better" radios cost at least 10x that