It all depends what you intend to use it for. We have both the new ipad3 and the nexus 7 in our house. The ipad is designed more as a device you would use at home or in the office and you wouldnt want to lug it about all over the place. The 7" tabs, like the nexus 7 (and the samsung tab 2 7inch etc) are designed to be a lot more portable. They will easily fit in a girls handbag, or in many coat pockets etc.. so you can take them anywhere. They are roughly the same size & weight as a small paperback book. If your going to lug an ipad about you may as well take your laptop. If you try holding your ipad for any length of time it soon becomes a bit uncomfortable - which is why everyone buys these cases which fold out into a little stand for them. Whereas the 7" tablet is much lighter and easier to hold.
The 7" tablet market seems to have gone through the roof. A lot of people see it as the optimum size for a hand held tablet. Even apple who stated that they would never make a 7" tablet are considering getting a slice of the action. For me the thing I had to try and decide on was would I really use a 7" tablet, when ive got an Galaxy s2 phone which does it all anyway.
If your wanting something which you`ll probably mainly use in the house, maybe just for web browing or looking at photos then the ipad would make more sense. But even then id probably opt for a netbook or laptop as i find it much easier to type on a proper keyboard. One thing I dont like on the ipad is the screen is 4:3 ratio - the same as old CRT tellys were before widescreen came out, so if your trying to watch tv or films on it, you either have to zoom in and miss half the picture, or loose 1/2 the screen with big black bars top & bottom.
My missus does love her ipad though, but from watching her use of it over the last month or so, she uses it as an e-reader most of the time - rather than use her kindle, she uses the ipad to show friends her photos, and she also uses it to go onto facebook. Thats it really.
That's pretty balanced to be fair mate, I think you've hit the nail on the head for me. I might see if I can have a little play on a Nexus and make up my mind