Its funny all this discussion, and the recent praise for the Tekin.
I have all of them and for the last 2-3 years since the first tekin R1 came out it has IMO been a dog. Strange feel, no grunt, totally useless for mod etc etc.
At first i also didnt like the SPX, but i think i tracked this down to soft lipo packs, it seems you need fresh packs for any of these timing speedies to truly work properly.
Last week i did give the RS Pro another go with a 10.5 at windsor, after a fair bit of tweaking it does feel pretty good, on par with the SPX that i have been running the last month or two, i have a few more changes to make and im hoping it will improve more. I can see that on a large track the Tekin would be good, as it seems to continue to pull.

Its amusing to see everyone clamouring for a RS now, when in 2 weeks the LRP will be here, and it will most likely be on par if not faster than the Tekin 203.

The free upgrades are awesome, but IMO it has taken 2 year for the upgrades to catch up with the STD SPX. And dont even start with the Team wave, IF you can get one going they seem pretty decent, but their claims of software upgrades were blown out of the water with the release of the RB-S (according to Max directly, the CPU of the 30 and 50 are not big enough for the S software)