I stopped by my local Chapters on the weekend to play with the Arc as well as compare it side-by-side with the Nexus 7. Very impressed with the look and feel of the Arc.
As mentioned above, I'm not a fan of the discovery bar. This is one of my main pet peeves with the Vox and I don't use the Mosaic widget anymore (which is a shame 'cause I really liked it before). I don't need this bar to find or recommend things to me, I wish there was a way to de-activate it.
Anyway, still undecided about which one to buy, but Nexus has the advantage at this point.