Here’s more for consideration;
You may have seen a commercial lately with a little girl ‘painting’ on a 20" Sony VAIO tablet PC - she’s using a digital paintbrush and the computer comes with ArtRage…so, I wondered if it supports use of a more accurate stylus.
The word from Sony tech support is ‘yes’.
Here’s the PC (ho hum specs, wimpy integrated graphics engine, questionable resolution - BUT it’s 20" 
http://store.sony.com/webapp/wcs/stores/servlet/ProductDisplay?catalogId=10551&storeId=10151&langId=-1&productId=8198552921666487725&XID=O:sony%20windows%208%20tablets:dg_vinb_gglsrch:e&k_id=2fa672c6-d377-7d28-62de-000015d745c7#specifications
And tech support pointed me to these styli and said they will be compatible (what is the plural of stylus…styli, stylus’…hmm) Sony Electronics - Televisions, Audio, Cameras, Mobile, Video Cameras
I’m skeptical but curious…would love to see this in operation vs. an EP121…they’re both spec’d wimpy for our uses but man oh man would be awesome to sit down and sketch anywhere with a 20" screen.
Anyone who has used an EP121 - I’m guessing there’s little to no lag with SBPro, but has anyone tried Rhino? SolidWorks?