Being a guy that used to lug around a laptop for many years, I feel the regular iPad is extremely portable, easy to carry, and not heavy at all. Guess its a perspective thing!
I can sort of see the appeal. I've got a 7" Kindle Fire HD as well as an iPad, and the fact that it will ft in a jacket pocket or the back pocket of a pair of jeans is significant - it means you can carry it with you and still keep both hands free like a smart phone, but you've got a more usable display. If you're constantly on the go, it's very appealing. If you're typically stationary when using your iPad, like you would be when using a laptop, the full-size version is better - ironically, for many of the same reasons Apple themselves said a smaller iPad is a bad idea, before they realized they could make truckloads of more money.