It's funny how defensive people get when someone slags THEIR choice of buggy
I'd go along with what Alex says purely because he has a wealth of experience, he actually owns or has owned a lot of different buggies plus he spends a lot of time trackside.
My own experience is limited to the EB4 I run, I know as an RTR it is not the best but as I bought a cheap LE kit it is now quite tough and with a decent engine goes well. Most guys I know locally run EB4's or Hypers but that is down to spares availability. If I went into my LHS and asked about X-Terminators or Rex-X they'd look at me as if I was from another planet, ask about most of the others they'd know them instantly.
When I was looking for a buggy I could only find one shop that stocked the Rex-X so I binned it as an option before looking at it, I assumed it must be junk as no one stocked it [&o]