Hi have the Nova 1624-44 since 2008 and at the time I would have the DVR if wasn't for the big price differences, (even more then, than now...!), I have no complain about the machine capabilities however, I never liked the constant belt change process, particular for me that I do so many types of turnings so, speeds have to be changed all the time and that really, bugs the hell out of me.
I don't think that I will ever own a new complete DVR but considering that, apart from the head/motor, everything is exactly the same on both machines, I may try to save and buy a new head the DVR XP one and, that will cut the cost considerably and also allows a spare head (original one) if something goes wrong with the new one where, weeks are "usually" lost before the problems are resolved...!
My suggestion is, DVR XP no doubt...!
Cheers
George