So, this is my review on the transfer 6 months on. Exact figures will not be made available, but maybe my methodologies or actions done may help others.
Any questions? Just ask.
1) Lack of features / loss of functionality
Honestly speaking, this has been a very small issue. Blogs, Albaums, Groups, Tags etc etc.... not missed. Smaller things such as members being able to edit their own titles were however missed (and still needed for 1.2). Some core items are definately needed, such as post edit histories and template comparisons.
2) Member interaction
Up across the board, people are more active and posting, PC's also up, new user registrations up. I think the whole user interation experience is greatly improved from vB4 and it shows. Enhanced search is working great and people are finding what they want much more easily.
Our protocol for the redirections was as follows.
Installed XF in our root (previously VB was in /vb/) did the transfer and placed the vb4 redirection script in the vb directory. At the end of the first month we used webmaster tools to force updates on the reamining cached /vb/ urls. At the end of the 3rd month we removed the contents of the vb folder entirely apart from the redirection scripts..
The results? Well we took a hammering in pure numbers. Simple as that. Whist we retained our google ranks and relevency in results, our pure numbers visitor numbers / pageviews got hammered. In the last few weeks they have started to climb back up, but still not to what they were before. Our returning visitor, pages per visit and time on the site are all up. So people are sticking around, but not as many are coming through the gates. Hopefully in 12 months this will have resolved out.
Update: The actual numbers wernt as bad as we feared, with a 12% change in Ajax loads over pure pageviews, the drop was only minimal, and when calculating figures based on the Ajax loads, our trafic over the 6-12 month period is up overall.
Fortunately due to a great relationship with Robbo our custom addon requirements have been replaced with his great service. We still lack a few smaller addons / functionalities but they are nothing noticed. Overall the quality of addons here at XenForo (aside from a select few) seem to be of higher quality than those at VB. I think the general feeling is many of the users of XenForo and addon creators arn't your "regular off the self websites" and are people with a bit more knowledgeable background, and this shows in the quality, functionality and features of the addons. The design of XenForo to work with addons probably helps a little also
Was it worth it? In one word yes. We took our time analysing XenForo for our requirements (almost a year) and when we took the change we felt confident it was the right choice. Even now, when comparing it to VB4 we agree the change was right.
For the near future XenForo will remain my top choice of reccomendation. We were early takers of VB4 and got burned on it. XenForo has delivered what was promised. I hope we start to see 1.2 updates soon to help plan for the future, but equally, we know that even if we have to wait for 1.2, XenForo 1.1 is a great platform we can evolve from.