Tricky one that even at 2k it's still about 500 quid cheaper than a new one.
Have you ever driven a dog engaugement box?
It takes a bit of getting used to and with straight cut gears and a massive clonk everytime you change gear it's a bit like driving a broken waredrobe.
The TKO600 has proven to take big power as with Rods car.
If it was a Road Car and the odd track days i'd probably go for the TKO600 but an out and out track car or race car I'd go with a T5 Dog Box.

I'm now in a position again to buy this box at it's original price and I'd have it in a heart beat at a grand.

Rich