Using an Android tablet as second PC monitor - good idea?

[WorriedNoodle]

I'm looking for a portable second monitor for my laptop PC (Windows 7) and was thinking of getting an Android tablet rather than a stand alone monitor to gain the benefit of having a monitor I can sometimes use as a stand alone tablet. Perhaps the Note 12 when it comes out later in year? I need portability, stuff I can put in my rucksack and travel with.

Anyone tried this out - or is it unworkable? I have tried it on my phone (Note 2) using both Air Display and iDisplay (Android/PC apps linkage). The latter uses USB but is still a little laggy for my tastes. The Air Display I found so laggy using WiFi to be mostly useless. Is there another way perhaps to speed things up?