Rock Maple hard? I pretty much thickness Rock maple all day long with my Jet drum sander. Of course I run it through the planer first if need be. But any local woods like Maple, Oak, etc are easily made to thickness with a drum sander and are NOT hard. I love when people say a drum sander is slow, well unless you are a cabinet shop pumping stuff out a hobbyist can get away with a drum sander instead of a planer. I mean does it matter than it takes 2 minutes for a piece rather than 30 seconds when a hobbyist may have only 20 pieces to do? I think not.
The drum sander of course is slower, but does not tear out wood either and it flattens stock, something a planer just does not do(if you don't understand that please Google I am not getting into another argumentative thread on that, what Americans think of as a planer does not flatten wood).
The best is to have a planer and drum sander, but if you can only have one and are just a hobbyist I would go drum sander every time, especially if you use figured woods a lot. Now if you are an impatient bugger or again, are pumping out 500 linear feet a day, yeah the planer is best(but you still need that drum sander for thicknessing, flattening and figured woods). You can also get an inexpensive little lunch box and planer and big drum sander as an option for those times you are in a rush.
I used the oscillating drum sander for 2 months and when it came out I really wanted it. Don't need it, sold it and am happy using my regular Performax sander I started with. In reality it is NOT faster using the OSC, once you get used to the non oscillating and learn which grits to use for which woods I find it is actually faster running the wood through the regular drum sander and hitting the wood for 30 seconds with my Rotex, if that's even needed.