id' recommend just picking up an older hotwire 2 for half the price. i don't have the bluetooth one and when I forgot mine at the track and tried to use a club member's BT HW, it was a pain and wouldn't pair so i just plugged it in and had it working in ten seconds instead. I don't see much use for the bluetooth function.
I like Tekin, i have a number of Tekin products, but the one thing that I don't love is how they don't release new things very often and the latest version ends up being many years old. But on a positive note maybe that's a GOOD thing that they don't need to update their products very often because they continue to perform very well over the years and don't feel like they need to throw something new out to market every year to "keep up" ... I'm still using a Gen2 Rx8 in my Sct410.3 and see no reason to replace it with the Gen3... A guy in my club that wins most of the time is still on a Gen 1...
Recently on another rig (2wd) I went with a Maclan ESC, partly because they don't need any device in between - you plug your phone or PC directly into the ESC with the included usb-C cable, it's great.