We have the combo unit and I am glad we do. I have never liked shlepping my dirty clothes to the Laundromat (no matter how close), hanging around while they wash and dry, folding them on heaven knows what kind of surface that I've tried to cover, and then shlepping them back home.
When we travel we do so for more than a couple of weeks at a time and the on-board washer/dryer is heaven. If we did not spend that much time on the road I would just take my clothes home to wash.
The machines are not without their idiosyncrasies, as many will attest, so adjustments must be made until you are satisfied. I wash and partially dry my clothes and then hang them on a drying rack or hangers to finish. This process "irons" them. If left to dry completely in the machine clothes have too many wrinkles for my taste. Jeans, in particular, require either ironing or hanging on pants stretchers. I always use a high quality liquid softener product.
Because there is no removable/cleanable lint screen, eventually your machine will plug up and stop working. When this happens several lights will flash. Calling Customer Service will get you to someone who will tell you how to clean the machine by putting it though various cycles. I expect this will happen more quickly if you wash mostly cotton garments. It took many years before this happened to us and the majority of our clothes are cotton.
All of this would be too much fiddling for some, but is worth it to me not to have to drag my entire wardrobe when traveling or, heaven forbid, go to the laundromat. If I had room I would consider a stackable unit, but if only room for a single unit I would definitely purchase a combo again.