JML Steam Bee:
Works quite well even though it spits out hot water with the steam, which means I have to put loads of towels down when using it. Tank is very small so needs refilling quite often, but you don't need to wait for it to cool down before topping up. I've had two of these; the first one was second hand and stopped working after a few uses. The second one is still working but I've got it in storage as a back-up in case I ever can't get my main one replaced.
ProAction from Argos:
Worked really well until the element burnt out. Twice. The first one took a couple of months to burn out but the second one broke after one use. Bigger tank than the Bee but having to wait for it to cool down between uses seemed to take ages. I didn't have to put towels down when using this one. The pressure was really good and I got really solid dreads when using it. This one was probably the best one I've used so far but I'm not willing to keep taking it back for a replacement every few weeks.
Earlex SC75:
I decided to give up on the hand-held steamers and get one with a much bigger tank. I thought this would have good steam pressure but it was rubbish. Took twice as long to seal dreads as the ProAction and left the room smelling strange. There's no trigger on this and the steam eventually fills up the room and leaves it feeling very humid. Also, the element is stupidly placed so that it's left without water coverage way before the tank is empty. The nozzle is rubbish and hot water collects in the nooks so that when you twist it to steam from a different angle you end up getting burned. Broke after two uses. Oh, and it was butt ugly
Morphy Richards 70455:
This is the one I'm using now and I love it. The steam pressure's quite good even though it's not as strong as the ProAction. I get nice, solid dreads out of this steamer and it seals quite quickly. The nozzle doesn't drip hot water on me and the tube leading from the steamer itself stays relatively cool. Unfortunately this doesn't have a trigger, which I would say is its only negative feature, so I do have to put a towel down and be careful which direction I leave the nozzle pointing when I'm not holding it. Even though it emits steam constantly, it doesn't fill the room up like the Earlex did. I've only had it for a couple of weeks but I've been using it quite frequently so I will update if this one breaks any time soon.
but that's cos of the hard water here.