I currently use AnkhSVN to integrate subversion into Visual Studio. Is there any reason I should switch to VisualSVN?
AnkhSVN is free (in more than one sense of the word) while VisualSVN costs $50. So right there unless I'm missing some great feature of VisualSVN I don't see any reason to switch.
I recently tried Ankh but quickly switched back to VisualSVN. Because:
For me, VisualSVN is pretty, but useless. AnkhSvn on the other hand, after it came in v2 as an scc provider, it works very good. VisualSVN tries to think for you, which is not an good thing, the user should be the controller, not the software.
The main thing is that VisualSVN uses TortoiseSVN for nearly all of its UI. So you only really have to set up one client (preferred diff viewer, etc), and you can take advantage of things like the same "Previous messages" button on the Commit dialog, whether you're committing from Explorer or Visual Studio.
I used VisualSVN until Ankh hit 2.0, and ever since, I've abandoned VisualSVN. Ankh has surpassed VisualSVN in functionality, in my mind, and all the 1.x perf and integration issues are gone.