Where you getting your numbers from yak?

Castle is always cheaper than Tekin... http://www.amainhobbies.com/product_...Package-2650kV and the Tekin will not handle 6s any better than the castle will (it will be a big sdtrain on both, castle warns you of this, whereas tekin expects that if you are buying their kit, you'd already know).

Don't get me wrong, if I had the money, I'd always go Tekin, but for crazy 6s speed runs, you don't need either. Get a Tacon 2200 and gear it to the moon. Neither of the 2650 will like 6s, they will get rather hot, you'll have downtime waiting for it to cool, or you'll melt it. Go cheap 2200 setup and rape it with 6s and gearing, it's the best trade off of speed/heat so I hear.