As to the VAG 401, we have had; a number of members, buy it in the past. The problem with them; is the lack of support and the unless, you know, what you are doing, not very user friendly.
While, not perfect; OBDEleven, is a wireless dongle, for your phone or tablet and has a app, which seems to be relatively user friendly. Again, when it comes to blocks and output testing; you have to know, what you are doing and this is a area, where OBDEleven, could be improved upon. I used VCDS, have since 2007; definitely, a solid VW scan tool and the support is amazing, really a bargain, for what you get.