I decided to sell my 457nm viasho. The head is calibrated doing 250mw and is stable.
The laser has a very good thin beam and ideal for graphics.
Below some pictures of the head and driver and some beam pics. The laser is less then 1 year old.
If you want a quality 457nm shoot me a PM. If you want cheap blue go for 445nm
http://www.viasho.com/e_457nm.htm
Mine is custom made and is doing 250mw from factory.
I bought it in march an i only had it running for a couple of times.