I host multiple IP.Board installations on my Linode VM (under a cPanel environment). I have had really great performance. On my Linode 1536 plan, I have 15 accounts and 4 or 5 IP.Board installations with plenty of room to grow (without upgrading my plan)! Highly recommended.
The top menu in the ACP of 3.2.0 that has the appearing drop-down menus is kinda laggy. I don't know if it's just me but when i go through the menus it takes time for the other to disappear so i have to wait before i can read the menu that it overlaps
I assume you put this in the Pre-sales Questions section because you want to see if it's possible to accomplish this with IPB before you purchase a license? I do not believe there are any native features in IPB to allow such things (don't know about 3.2), but there may be a module or application that exists to do that. A work around that you could do is have the board you want to have mirrored somewhere else export an RSS feed and import that RSS feed automatically on the other forum, but that simply accomplishes your desire to have topics from one forum mirrored on another.. this doesn't work for replies or accounts or anything else. From what I can tell, this is a task that would require a custom application/module for IPB. You could always write a code to mirror some of the table rows for posts in MySQL and import them to the other database, but I think you are looking for something on the frontend