Hi,

There is quite allot of these available these days, at a glance they all look the same, however, see the link below for a detailed explanation of what is available and what the differences are.

Basically from what I understand the issue with the ISIS is that it uses a 10 spline square tapered spindle which requires a smaller ball b-ring that will wear out faster.

The link is: http://en.wikipedia.org/wiki/Bottom_bracket