I used to have a swb high roof, absolutely loved it, and still miss it 3.5 years on!. Built like a brick s**t house, nice high driving position, extremely good steering lock (like a London taxi!), extremely good heating and ventilation, very comfortable and refined cab, i could go on, but you get the picture!.
Drawbacks, the only one that springs to mind is the timing belt, it is a big (expensive, £700+) job, so if buying used, bear that in mind. For the '00-'06 versions (2.3) the recommended interval is 240,000 kms (i think that is around 150,000 miles) OR 5 years, whichever comes soonest (i was actually looking at one this afternoon, that's why i know!).
I got 29mpg average, which i think is pretty good for a van like that, but i don't drive hard.