40mm lower Eibach springs and 17" rims - any gotchas?

[steve955i]

I've been looking at a 325 cabrio on ebay with 40mm lower Eibach springs and 17" rims - seems to be a common modification. So presumably the bigger rims change the final drive ratio, increase the ride height 1" and reduce wheel arch clearance 1" - then the springs drop the ride height (40mm less 1"?) and firm up the ride. Is this accepted as a good mod combination or are there any gotchas in terms of harsh ride, ground clearance, arches and bump stops or uneven tyre wear? Thanks