At our local track in Torres Vedras, Portugal,(Indoor RC Oeste, 1/10TT Carpet) we just upgraded to the new decoder box. The MRT PTX transponders don't work. 2 pilots were using them and in 10 minutes they just counted once.
We also have the old track rechargeable transponders and they work just fine with the new box. Also the RC4 hybrid work whit no problem, never missing a lap. We haven't tried yet the new RC4(3 wires), (no pilot as them yet).
I'm using the Ethernet connection on a laptop with Sparc and everything works just fine.
We also use the program Laps Free (this one with serial cable whit USB converter).
Not fully tested yet but i did a small test ant it seams that works OK.