I had warnings in Google Webmaster tools about the sites not being mobile friendly. I notice that Google started to display my forum as Mobile Unfriendly.
Eventually I got round to an Upgrade. I had been waiting forever for Simple Machines to get their fingers out and go responsive. Whenever I asked them when the new version would be out with a responsive theme, i got the standard answer "When its ready and not until".
No amount of explaining that our sites were suffering in Google and our incomes were down seemed to matter to SMF. I wasnt the only person asking the questions and their standard reply wasnt nothing short of rude.
I finally made the shift over here a couple of weeks ago. With the help of forum member @JulianD the transfer went without a single glitch. His price was more than reasonable and he was a complete professional in dealing with me. For paid help I would highly recommend him.
Since Migrating my site is back performing well in google Mobile. My Adsense income for the site is back where it was in March and following the long term trend.
I assume Google has some Algorithm that knows if your site is viewable on Mobile and they rank your site higher and give you better paying adverts if it does.
The support here has been excellent. It seems Brogan answers your questions before you even ask them.
Many thanks to XenForo for your excellent software and the help of the admin and community.
Please can I have another copy free of charge for my second forum
Oh yeah and if your looking for forum software look no further. currently I run one on Xenforo, one on SMf and one on Burning Board. the support at Burning Board is also very poor, and despite all the Hype I do not like the product one bit. I wish I had opted for Xenforo for that one too.