Well the Nexus seems to have a good reputation and customer response seems to have gone well. The Arc has better specs/hardware but then Kobo is Kobo.
The new nook has probably has the best specs of all the current 7" tablets and their products have been pretty rock solid, at least for me. However, it is a closed system and you will be locked into the B&N reader, which is ok, but lacks the features of a "Mantano, Cool Reader or Moon +" all available through the Android market.
I'm going through this exact same question myself and as much as I like the B&N products, I'm tilting towards the Arc or Nexus because I prefer an open platform. I do intend to look at the Nook products however before I commit myself to buying anything.
I am also hesitant to buy from Kobo until I hear other owners opinions however it does appear that most people feel good about their "Glow" purchases.
Last edited by fbrII; 10-14-2012 at 06:19 PM.