I know several folks who bought "all in one" machines. They worked OK, although the software in most cases was totally OTT. They provided a nice, simple photocopying facility.
But when any one bit goes on the blink (which it will do, eventually) you have to replace the lot.
If you have the desk space, separates are a bit dearer, tend to work at least as well, and seem to go on for ever.
I just scrapped a 12 year old colour scanner. It worked well with XP, but there isn't a Win 7 driver. I put it on the shelf when I went to Win 7and threw it because there isn't room for storing old stuff in the new house.