My DF already has the 3 racing conversion but to be honest it's a bit of a pain. I made up an undertray using lexan sheet, and bolted it under the chassis but to remove the battery requires major surgery! I'm currently running a Trakpower lithium in the DF, but I've heard rumours of a new saddle pack lithium battery coming out soon which I'll definitely use for the TRF, so I may as well use that in the DF as well. Standardisation is good.
I have got a 5 stars centre CV driveshaft, the only one I've ever seen, got it off jr-rc on ebay and since I bought it I've never seen another one. I'm running a centre 1-way and I did try making a front 1-way out of one from a TA-04, and grinding the centre of a front diff gear down, but I couldn't get it accurate enough and it kept stripping drive bevel gears. It did handle extremely well with both a centre and front 1-way though. If it wasn't for the fac that I've just spent £400 getting some new brakes and HT leads for my car, I'd definitely get one right now. I'll probably get one next month when I've been paid... along with a KMR chassis and the Azarashi body...
-Steve