After having two E89s with the over-complicated roof, imagine my pleasure when I bought a Z3 with just a single hydraulic ram operated off one AA battery and a piece of string!
My Z3 has a manual roof which I think is perfectly suited to the car on the basis its better to be on the outside when you retract the roof to ensure the plastic screen folds correctly.
That said the E89 folding metal roof creates for a much more year round useable car and despite the complexity of the mechanism most of the issues are well know common failures that can be avoided with prevenative maintenance.
However, if the worse does happen there is a wealth of independent support available via the forum or from local specialists
