I've used similar ones several years ago. Basically it's a curved metal platen with a heating coil strung underneath it. (The one you linked is two-sided). The apron clamps tightly over the print holding it flat in contact with the heated surface. The prints tend to dry pretty flat with maybe just some edge ripple. The two-sided ones can be loaded on both sides and flipped, but of course the top side dries fastest so you have to work out a system for loading,flipping and removing the dried prints (or you can just use it one-sided and not bother). So all in all, it is probably faster than air drying but the trade-off is that it requires more tending. The problems are: possible fixer contamination of the apron over time and some archivalists used to scream bloody murder at the mere mention of heat drying (which is odd since I rarely heard them bitch vehemently about dry mounting).
Often the platens are actually ferrotype tins if you are into that. For that you squeegee the prints face down onto the perfectly clean, polished plates and leave the apron up. When they pop off, they're done.
Hope this helps.

-Neal