I'm starting to redo all of my 2004-2005 vintage HaT Romans and Carthaginians onto Masonite. The kids and I have been using this for all of our 1/72 fantasy armies for a while. I'm also adding a flex steel layer to the bottom, so they will stick firmly to the boxes for transport.
With the French and Indian War figures all rebased, I've now got the balance of this project and Medieval Mayhem to go. After that everything will be on 'permanent bases' (and magnetized) and I don't intend to go through this again.
I also am splitting the rest of my Sheriff and Robin Hood figures off their penny bases, which is a bit painful. They'll be collected into fantasy along with the first group I rebased a couple of years ago.
Reminder to self: write the rules to match the bases!