We have two washer dryers, one upstairs for my son, one downstairs in my granny annexe ensuite, and a tumble dryer, all large capacity.
My AEG washer dryer is great for doing small amounts regularly, just for me. However, if you are doing lots of sheets I would recommend using a tumble dryer instead.
My old dryer died recently, and I bought a new all singing and dancing "green" A+ Hotpoint condensing dryer. It lives in the conservatory outside my bedroom door. It's great for doing the cotton polo shirts I wear most days, it dries quickly at low heat because it has special paddles inside, not a smooth drum BUT it doesn't do big sheets well, it has a tendency to screw them round and round!
So first, think carefully about how you like to wash. Small loads regularly, washer dryer is fine. If you like to have a "wash day" with consecutive washes, get a tumble dryer instead.