Having done a bit of SMD work with this device now it's worth passing a few comments. First of all it makes an amazing amount of difference to SMD soldering in general. I find myself no longer using the magnifier because the component is securely held and I can concentrate on the soldering.

The spring can work its way sideways, I occasionally have to recenter it. There is also the possibility of it flicking a component off the board if the component isn't seated well. I had this happen on a reworked component where I evidently hadn't desoldered the pads well enough and there was a "hump" of solder. Not too bad when it's a 2p chip resistor, though I can see it would be a disaster with an expensive and exotic semiconductor.

All in all though, pretty happy with this device.