Ha. Within a couple of days of me changing over to the BuildTak print surface Ultimaker have announced a Heated Bed kit for my printer. Oh well. There may be some second hand printer parts going up for sale soon.
I've always wanted a heated bed for my printer. Una, my Ultimaker 1, does a lovely job on very small objects, but on larger ones there is always some warping as the printed object cools and contracts, lifting the corners and turning any rectangular object into a cushion.
A heated bed solves that. It also gives you a smooth glass surface to print on so that you get lovely shiny prints. The upgrade replaces the entire print assembly, which is also cheering for me as I made a bit of a botched job of making the original, giving Una a rather lopsided appearance. The new bed should put that right and so I've ordered one.