Well, it's arrived... I bought this:
It seems pretty good so far.
Only switched it on for testing at the moment so not used it for an extended time but there's absolutely no suggestion of any heat
build-up (which is one of its selling-points on the advert): some reviewers of other models have complained they get hot.
Most importantly (for my purposes) it can shine through at least two superimposed sheets of 190g water-colour paper
- at first I thought it could barely manage a 190g over an 80g BUT that was because I first switched it on in a fully daylit room.
I then drew the curtains and BINGO the lightbox performs perfectly.
The light intensity can be stepped up or down by holding down the ON/OFF touchpad.
It comes with a USB cable for powering either from a PC or direct from the mains using a phone-charger (as per the instructions).
Only thing to watch is it's said to be A3 but the active area is actually 400x300mm which is a tad less than A3 (but that's no problem for me).
There are quite a few cheaper ones out there but also lots of models which are 10x the price and more.
I couldn't tell you how this compares with others, but for £29.99 I'm very happy.