I changed out today from my last VB site to XF, using Joomla as the CMS. You can clearly see when VB4 was running, the few hours of upgrade spikes, then for the last hour nearly of the snapshots you can see the load take back up. When I took these snaps I had around 300 back online again, average is around 400 online. Even that 100 extra isn't going to make much of a difference, as the load barely moved from when users began coming online to the end of 30 minutes of it being open with 300 already back on. What I knew before I changed? That my server costs would be much, much lower. If I kept going with VB4 I had to upgrade again to a dedicated vs. a hybrid solution. I changed over to a more resources recently, and VB4 pretty much sucked up everything immediately, as it was extremely slow on the ServInt Ultimate VPS... so instead of upgrading further, I knew the change would seriously reduce the load... and my expectations weren't wrong. Proof is in the pudding! An XF endorsement for savings if I could ever give one... Server costs! The mysql change just blew me away... again, I expected it, and XF didn't let me down. Now fully converted all my own sites to XF and couldn't be happier!