It’s difficult to get your foot settled on the Xs. The main reason for this is that they’re more of an ‘M’ shape.
The result of which is a big gap at the back of them, which although it allows mud to clear, leaves a gaping space at the back of the pedal causing your foot to feel unsupported.
The result is that you never really feel stable on them and end up constantly adjusting your feet before you even hit any fast sections.
There are plus points, such as the replaceable pins, the chromoly axle and the sealed bearings, but for this money there are a lot of better options available.