Dear colleagues!

I use Nikon F5 camera. Please give me an advice, which Right Angle Viewfinder Attachment to choose? DR-3 vs DR-4 vs DR-5?

DR-3 are available on eBay, there for I'm thinking: is there sence to wait for DR-4 or DR-5, or DR-3 will be enough?

P.S. I don't have too much tome to wait till "newer" models appear on eBay, and I don't see any in B&H.

Thanks for answers!