Never had a single problem with my DC02 or DC05 (and the only reason I had to replace the 02 was because I left it with the ex-wife!).
I raved about the 02 to my girlfriend but she wasn't convinced until we bought the 05. I made a point of vaccing the house with the previous bag vac she had, then re-vaccing it with the Dyson. By the time I had done the staircase and landing it was FULL - mostly cat hair and her hair! That was a damn good demonstration of how much better it was than the previous cleaner if nothing else.
One thing that I really like about the 05 is that it's the 'motorhead' model, which has a motor powered rotary brush in the head. I notice that later models went over to using a turbine powered brush instead, which seems a really retrograde step. Is a motorhead available for any of the new range?
Personally, I recommend Dyson to everyone and would never consider buying anything else.
Steve