I used Switch from my N95, and Sync on my N900, and it worked fine. However, I did find a slight issue using PC Suite to sync.

From what I can tell, the N95 and N900 use different "fields" (apologies if that's not the right word).

If I sync my N900 to outlook, everything copies to the PC fine, but if I edit a contact in outlook, and resync back to the phone, the "Mobile" field is unsupported, and promptly discarded from the mobile.... leaving a contact with no number :-(

If, however... I created a contact on the N900, sync, edit, resync in the same way, the "Mobile" field survives the transfer..... weird.

If you don't sync to the PC though, then you should have no problems