We had some of them at work and as a business workstation they are quite handy! Even though small and you'd think they should overheat, they are very quiet as the models we used were cooled by liquid filled pipes.

But one the other hand I suspect they wouldn't really be fit for heavy graphics editing (depending on the graphics card, heat could be a problem).

And another downside: Don't even think about changing anything inside as they are really crammed! I was about to add some RAM to one of the Shuttle PC:s and had to give up.