only issue with the clarke is that the threads do come undone... so threadlock them!
And the rubber constantly gets stuck on whatever you're jacking, retrieved mine from the roads a few times...
Jezza, I got a 2.5T SGS one and it's fairly good, had to bleed it a fair bit when I first got it, but was well priced and hasn't shat itself even lifting my mates transit.
Clarke one, £/abuse has to be the best jack out there, I've had mine 7 years now, and it's still going strong!