Assuming these are the same rolling stock at the DB City Night Line trains that used to run Munich-Rome, I'd say absolutely worth it (I've ridden them between Munich and Italy a few times). Nice to have the shower & toilet w/o having to share, though it is a bit small (shower head also serves as your sink faucet).

I seem to remember space under the bottom berth being quite short as the bottom berth folds up (or down) to become a day-time seat. Main baggage storage is the area above the door (or really above the corridor) so you have to heave the bag up there. You can in a pinch, use the space where the door to the adjoining cabin is located.

What we did on our most recent trip was stock up with goodies on boarding in Rome and ate dinner in cabin. You could perhaps do the same in Wien.