I have upgraded my blog from b2evolution 3.x to 5.0.7. I have experienced a lot of performance issues. I did some performance tuning. Maybe they are useful for you. Firstly, I cleaned all unpublished comments. That makes the database much smaller and faster to run. Moreover, I went to System->General, and unchecked Log hits for every public page. That save the execution time for each page. Then I deleted all hit logs in database. For the same reason, I wish the database to be smaller. These information is not very useful. I have other analytically software to track the visitor count. I wish those tips can help you have a better b2evolution.
I just got a new website built which is a Gantry template. I got some error, e.g. Fatal error: Out of memory. That is from Gantry's CSS LESS compiler. I tried to comment out the codes to by-pass compiler. It does not 100% work. Finally, I put a request to web host for increasing the buffer to 128MB. Then all works fine.
(Note that, I know you can use define function in php to increase your memory buffer, but some web hosts will not allow it.)
I am just about to build a new website for a client with Joomla 3.2. However, after I checked the requirement of Joomla 3.2, that requires PHP 5.4+. That doesn't support by the client's webhost yet.
If you plan to have Joomla 3.2, please check with the web hosting company first. I have worked with a number of budget web hosting companies,they are using php 5.3.x. Thus, before you install Joomla 3.2, please please check the php version of web hosting company!
When I release a website from the staging to production I got an error (500 - An error has occurred. XML file did not load.) when I click the template in administration interface. The solution is easy. Just re-load templatedetails.xml in your template folder.