Would I notice much difference with a high spec TX
 

I use a Flysky FS-GT3B, which compared to my standard HPI TX feels amazing, but it makes no difference to my driving. Do the top transmitters such as the Futaba 4PX help to control the car better in any way?

Buying a decent transmitter was one of my best investmensts. I was a sceptic until i bought a Sanwa set up and couldn’t believe how much better it was for me. At first I literally hit every corner as the car turned so much earlier than I was used to compensating for!
I went from an acoms 2.4ghz steerwheel to a Sanwa mt4s at the time, wish I had done it sooner!
Also getting a decent steering servo upped the game as well.

I crashed more, always hitting the apex. Instead of clipping it.
Didn't realise how much compensating for lag (by a tiny tiny fraction of a second) and precision would affect my line.
That's from a DX3R Pro to an M12.

It wasn't actually why i sold the DX3R, the occasional drop outs at the end of our longish track (always on the same 180 degree corner) were driving me nuts. Had the M12 for ~18 months now at it's not missed a beat. Or dropped out.

All crashes are now the drivers own fault.

I'm sold. What sort of specs do I need to look for in a good transmitter? I notice that Sanwa do 3 levels, is that performance or features that make the difference or both?

It does make a bit of a difference, I went from a CoreRC to a Futaba, I found I could catch those slides before they actually started. It's not gonna turn you into a driving god but it certainly helps you to be your best you.

Anyone any experience going from Sanwa Gemini X to Sanwa Exzes?

ive always used futaba 3vcs transmitters, i have 4 of them and i decided to purchase the sanwa zz, what a difference, the response time is unbelievable and i think the upgrade was the best thing i did, not keen on the 2 battery door tabs, they only just lock in but other than that its the best transmitter ive ever owned.

Depends on your budget. I know a man with a Sanwa Mt4 up for grabs (if he still has it) and that’s a quality wheel.
I would personally steer clear (no pun intended lol) of the lower spec transmitters unless you pick them up really cheap.
Mt4, MT4S & upwards for me.
I’ve no experience of Futaba or KO so I wouldn’t like to comment on them.

No discernible difference. You're down to maybe one or two ms difference between the two.

I have, I never liked the sticks on the Gemini X, didn’t have enough travel on the throttle stick to brake the way I like.

The Exzes is much better for that.

I've just picked up a Sanwa Gemini X 2nd hand, superb transmitter.
Is there no way to have equal travel for brakes and throttle?