How do you collaborate on video reviews with clients?

Hi

I have been trying to find a solution that allows very easy client review of work for mostly video reviews but also images, pdf, word docs etc where a client can request a change, that change is forwarded to users who would manage a change request, assign it and if somebody fixes that change then that is also logged, client gets notified to approve change etc. etc.

I have looked at www.reviewstudio.com and liked the video annotations part but also felt it lacked in other areas like storing change requests, agreed changes, declined changes and general discussions for an entire project rather than a single "review".

I currently use Dropbox and Emails which results in many folders \v1, \v2, \v3 etc.  I want to reduce duplication and project fragmentation while improving the client review process at the same time.

What solutions do others use? 

Thanks for any advice.

Geoff