Originally Posted by tobyzhang

There are 2 concerns before I'm set on buying the ultimate.

1. Is the gear diff improved from the XI? I think the XI diff is very poorly produced and the internal drag is unacceptable. It is absolutely horrible compared to Tamiya's and I've fixed it by going to tamiya 416/ 417 gear diff and sanded down to reduce width a little, and switch to 37 pulley up front. If the new diff is not decent, I don't think there is another brand gear diff to replace that 40 tooth pulley.

2. Does the ultimate accept XI short shock tower? Do they have the same hole patter? I would like to have the ability to fit my low profile tamiya bodies and experience says the low profile tower will work. I don't want to lose that ability.