I had a chance to import from DownloadsII over the weekend and successfully imported 3,415 files but did run into some problems, from previous post, vBDownloads in VB3 did import DownloadsII files!
After importing I set up the permissions and categories and tried to edit a dl and ran into these problems that were answered previously:
http://www.dragonbyte-tech.com/f79/how-do-i-add-thumbnail-12948/
http://www.dragonbyte-tech.com/f79/upload-controls-do-not-work-12949/
I then tried these steps from this thread:
http://www.dragonbyte-tech.com/f79/no-sidebar-12950/
The issue is most likely that your vbulletin_css directory is not writeable. You need to CHMOD it to 0777, then go into your vBulletin Options -> Style & Language Settings -> Store CSS Stylesheets as Files? to No then switch it back to Yes.
Still no change in FireFox, can't see uploaded files when editing, then I installed Chrome and everything is there but doesn't work with my FireFox.
About the importing, It didn't import category descriptions no big problem for me, but major problems for me are (would require 100's hours of work):
Didn't import file descriptions
I believe vBDownloads is importing the File uploader and
not the Author field in Downloads II, they can be different and are in my DownloadsII. In the templates, I have the uploader name disabled in DownloadsII because most of them are me!
Screenshots and Thumbnails, didn't expect this to work but it's a major problem, I really appreciated the picturestorage folder, DLsII should have done this as well. Unfortunately, inside this folder after importing are just 3,415 "no image" images. After testing, I'm still trying to figure out what happened, no images appear in the program except for the "no image" file but I think vBDownloads tried to import thumbnails but not screenshots because I see many, many new files, both files and new images in my ftp "downloads" folder from DownloadslsII, The new images after importing have a "_thumb.jpg" ending . Could it be that the thumbnails were imported but not screenshots into the downloads folder and not into the vBDownloads data base?
After testing vBDownloads another major problem for me, I tried to change the imported Authors name field (see above, I think it's actually the uploaders name from DLsII) to an actual Authors name that doesn't exist in my forums, doesn't work, tried to leave it empty, didn't work. You can change it to a user that exists. In DownloadsII, you can change it to anything, that's very important to me or at least be able to leave it blank so you can mention the real author in the description.
Sorry about the long post, as mentioned earlier I really like vBDownloads vs. DownloadsII and noticed that I have some other products installed in my old vb 3.8.1 that look like are here now, (Post Thanks, VBShout, VB Credits and VBCommerce) perhaps I did some stupid stuff or some of the major importing problems can be alleviated by getting the Pro Version or by upgrading to VB4 which as mentioned in a previous post currently isn't possible for me.