Never driven a 90, but, as has been said by everyone else, the only thing that really lets a 110 down is the turning circle.
Not a problem normally, you just swing more into tighter corners.
Where I notice this most is reversing into a parallel parking spot. Where as a normal car (and presumably a 90) can reverse in at an acute angle and then swing the nose in, the 110 has to take much a shallower angle in and then manoeuver the nose in. Just practice really.
Can't be beaten really though for the space/people you can carry, plus you've the option of a longer roof rack.
I keep meaning to check, is the loadspace in a CSW 110 exactly the same as a 90?