I prefer to have them seperately, you can be drying and washing at the same time, also, the drum is smaller on the washer/dryer and so you need to dry only half a load at a time and even then, the clothes do tend to crease, I tried one to save on space, but was not impressed.............Hope this helps.............welsh
We inherited a washer dryer from the previous owners of our flat. The dryer was pointless, as it took 4 years (slight exagerration) to dry anything, and then the clothes smelt yuk because they'd been in the dryer for so long. Totally pants, and we ended up never using the dryer function.
I have been told by a repair man to always go for the model with the least options and as mechanical rather than electric as you can (e.g push buttons if possible)- they are far more reliable
I too have had various washer dryers for years and would not want anything else. That said I only use the dryer function for occasional finshing off or emergency and not for drying whole loads.