I've messed with them and I think they are amazing but that was when you could pick them up for $1000 no problem. The divorced transfer case makes it easy to put whatever motor in you want. Swap it with a 100 horse whatever and put the axle under the spring and it's superior to most any side by side with a ton of flex and it's nearly impossible to get stuck.
I loved my 3TC yota motor with 32's and I'd probably do something similar again if I didn't already have a thousand hobbies. Even as overpriced as they are now, I think they are cheaper than a side by side and street legal and any car is gonna be easier to customize for cheaper.
Easy to build as you go and they're so simple that you can find a way to do anything you want with very little effort. But yeah, 64 horses stock won't keep you happy long