Well worth it if you have a compatible LG monitor!
I already have the i1Display Pro but bought one of these LG ones just to take and use on my 34UM95!
See mrk reviewing it here:
Why did he say there is little difference? Did he compre the LG results to a delta chart ? For me when he switched between the two results I could see big differences in the picture. Anyway it would be good to get pcm2 and badass's review on the coloromiter.
But for £30 even if it is restricted to certain LG screens it does look like a terrific buy as it's quick and easy to calibrate your screen. The i1 display pro with third party software would cost way more than that.