You definitely do not need a wide board in size 10.5, especially with newer style boots that have smaller footprints. You will probably appreciate a narrower board with the smaller boots depending on how you ride. If you ride park all the time, it is not going to matter. If you enjoy freeriding, you should probably go ahead and upgrade. The bindings might still be ok, but probably sloppy. Size l is going to fit better than xl I would imagine.