At my LHS touring is the main class. At one time the vehicle battle of choice was between the XXX-S and TC3. now the X-Ray is the rage among the pro guys.
The X-Ray is a great vehicle, you get what you pay for there I will admit. I am not a big belt fan but if I had to get a belt drive vehicle, the X-Ray would be on my list.
As for the XXX-S, guys are able to get it to work, but if you get one, make sure you get a GP+ model. When I got my XXX-S I couldn't get it to work for me no matter what I did. it wouldn't turn at all well until I got some PRP shock towers.
The TC3 is my car of choice right now. I have upgraded mine with BMI Chassis, but even without it, I was better driving it than my XXX-S ever.
As for the Pro-4, word I have heard is to dump the one-way and get a standard diff right away and the car is awesome. Something to consider.
No experience with the Yok.
For you, even thought I run a TC3 and love it, I would say go with the X-Ray or Pro-4 since you will feel that wow of hey this is a new car. My TC3 only gives me that wow when I look at the BMI chassis