At Best Buy today, I checked out the various tablets.
All of them had a massive anti-theft device attached to the bottom. Like a big plastic half a tennis ball glued to them. Except Apple's iPads--those had an anti-theft thing like a little disc the size of 3 stacked pennies.
For a device you're supposed to HOLD, any weight advantage those other tablets have by being smaller & plastic is lost by their big attachments.