VectorQuantity

If it's of any help to anyone the approximate cricial focus zone (depth) for different F numbers for blue (470nm) which is the most sensitive is along the lines of: (the ratios should be correct even if absolute values don't tie up with your calcs) F2, 4, 6, 8, 10 ,12 9, 36 ,82, 146, 229, 330 microns This is just to give an idea of sensitivity to F number, in practice you'd want to place focus within the CFZ up to 10 times better than these figures.

I've had a Sesto senso (V1) with flexible couplings fitted to three different WO scopes. The connection method to the outside of the focuser collar is a nice idea but assumes the focuser collar is concentric with the focuser shaft. On two of my WO's it was not concentrice and despite all attempts at alignment you could actually see the Sesto senso 'wobble' as it's stepper rotated. Luckily these scopes had relatively long focal lengths and a non-critical focus zone. To just compare the EAF/Senso/WhateverFocuser by itself is difficult maybe impossible, leaving out the attachment method and step size other significant variables are the focus software and scope focal length (focus criticality) both of which have large effects on the focus outcome.

Having used both EAF and Sesto senso (and Moonlite) on multiple scopes. ZWO EAF works well, as long as one of the ZWO choice of mounting plates fits your scope, or you adapt a ZWO supplied one. Backlash seems good, accuracy seems good, undecided about load handling. Sesto senso 'can' be fine but suffers from it's mounting method. The attachment point being the outside of the focuser train which is not necessarily concentric with the focuser shaft. If the focuser shaft and focuser 'outer' are not concentric the Sesto senso will 'wobble'. Backlash seems to appear if 'wobble' is present, otherwise accuracy seems good, load handling seems good.

These light pollution maps are quite useful https://blue-marble.de/nightlights/