There has been problems with the wiring from electric shifting being cut by irregularities in the shaft of the cranks.

This hasn't occurred a whole lot with the Shimano 24 mm shaft cranks but often enough that the FSA EVO 30 mm cranks offered worries to the pro mechanics. The BB90 is a shell that the electric wiring has to go around and is a royal pain in the ass to install. The besst way is to install it AFTER the wiring and there are holes in the shell so that you can use your fingers to push everything out of the way. Once the shell is installed, the cranks are entirely out of the way of the wiring.

The 386EVO cranks are lighter than the 386EXO buy a significant margin so it is nice to use them. The larger diameter shaft is mechanically a lot stronger and more rigid. Plus if offers a better carbon crank to shaft connection.

I used them a lot on carbon fiber bikes when I was looking for the lightest bike. But then I discovered that anything under 24 lbs climbs as well as anything else unless the climb is very long. I was riding steel bikes up the 20% grade from the parking lot to the lookout platform on Mt. Diablo for years with very heavy bikes and even in as poor a condition as I presently am with winter weight gain and an almost complete absense of climbing roads left in the bay area, climbing around the keep out fence on Redwood Rd and riding to the to using the by-pass around the entirely collapsed section of road, I have absolutely no difficulty riding up that climb on the Land Shark which in that condition was 26 lbs.

The Basso Loto is a little over 22 lbs ready to ride and the Allez a little lighter. So I will just ride slower and with any luck at all they will repair Redwood Road and I will be able to take the extra 10 lbs off. That makes FAR more difference to climbing than using a lighter bike.

And it sort of happens suddenly. You are too heavy and you're climbing slow, then you get some weight off and you begin riding a LOT faster which causes you to lose more weight which then makes you ride faster. Now when I say faster, I am still slow but faster for me and with a great deal less fatique after the ride.

There's little to no reason to have a super light bike even if you're riding crits since weight only makes a difference when you're accelerating and most crits are on courses that need good cornering tires more than the ability to accelerate out of the corners.

Most of the local crits hardly require you to slow for corners if you have the guts.