The big metal ones everytime, I started with the plastic hoselock things, eventually got one of the metal type ones from Cleantech, best upgrade for a long time!
The difference between the plastic and the metal ones is totally enourmous when it comes to winding it in, even with the best part of 100m of standard size tricoflex hose draped 80 metres up the road.
The worst leak I've had so far is a couple of drips here and there.
As for freestanding or bolted down?
Mmmm....sometimes I am pleased to have the scope that not having it bolted down gives me...and then sometimes I wish it was bolted down tight!
Ideally I think some contraption that would allow me to swivle it out of the rear of the van, and then able to lock it in place in the centre or to either side, plus having it on a plate that would allow it to rotate in whatever direction that gives me the most direct route to where I'm working....
Ian