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So I too started with the Logitech Ultrathin but 90% of the time I like to carry my iPad Air (1) with just the Apple cover. I was wandering through Best Buy awhile ago and found the Logitech Keys-To-Go.

http://www.logitech.com/en-us/product/keys-to-go-ipad?crid=1608

I stuff it in my bag and pull it out when I need a keyboard. I doesn't add much bulk to my bag and works great. (In fact the bulk is about the same as the iPad + the Ultrathin.) It is not backlit (not a real issue for me) and it doesn't physically attache to the iPad so no lap-surfing but that is not in my use profile either.

FWIW
DLM
 
First they took the keyboard and sold us a PC without keyboard and named it tablet. They told us "you don't need keyboard, use the screen which is as good as keyboard". Now they add the keyboard and sell it separately for $189 and they tell us "this is the ultimate solution you are looking for a long time."
 
First they took the keyboard and sold us a PC without keyboard and named it tablet. They told us "you don't need keyboard, use the screen which is as good as keyboard". Now they add the keyboard and sell it separately for $189 and they tell us "this is the ultimate solution you are looking for a long time."
To be fair, the one selling the keyboard are not the one who sold you the tablet.
 
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