OT 123D Circuits

I have been using Autodesk 123D since it first launched but I have been using the 123D Circuits app a lot the last couple weeks and figured I would ask here if anyone else is using it if you use Arduino any. I have seen some posts on single board controllers before and this is a good sim tool.

I do a bit of mechanical also so I use the whole suite of 123D apps along with my MakerBot and do some things in Autodesk Inventor. All the 123D tools are fun to tinker with.

Here is the link http://www.123dapp.com/circuits