We found much the same polling our approved PCB vendors in UK/EU and far east. 

It used to be the case that PCB vendor front-end (and paste stencil manufacturers) preferred ODB++ over Gerber and even in some cases offered a small financial incentive to have data in that format, but most common data format remains Gerber because that is still what everyone uses.  Chicken-and-egg. ODB++ is certainly a more "intelligent" and complete dataset. No-one was much interested in IPC-2581 at all, so I don't see that gaining traction any time soon at least on this side of the pond.

If the free viewer for ODB++ was easier to use, I'd be much happier to move to that format, but it needs to match the ease of using GC-Prevue and Gerber files and it really doesn't currently!