25mm deep to hold larger bits. Ever so slightly wider bit slot should make it easier to seat bits at their full depth.
v1.1 has a more rounded base which should be more ergonomic but may be somewhat less easy to print with the steep overhang.
The fit may be a tad loose with some bits, though the fit on the widest of mine have been perfect. Try scaling down the x/y axis 2-3% if yours are on the skinny side.