I use one as a daily runner and haven't been dissapointed. Just like any other vehicle problems will crop up, when they do, if good quality parts are used and knowledgeable hands attend to it there is no issue. Also goes without saying that routine and preventive maintenance should be carried out diligently.
Parts can be expensive if you only source from main stealers. E bay is a good alternative for small & medium stuff.
One of the weak points is the clutch cylinders... tend to leak ever so often. But the replacements are not that pricey and replacement is a simple DIY. It might have something to do with the brand of brake oil used as IIRC the manual says use only Castrol... I havent used it and have been using Lockheed from day 1. Next time I will switch to castrol and see whether there is actually a difference.
Engine wise upto 300Tdi, very simple and economical.. TD5 onwards it starts getting pricey...
But its not for every one.... if you want a quite, comfortable, easy, sedate ride with no surprises, then forget it... then again if you're a bit of the adventurous and mechanically inclined kind... well then... by all means go for it.