If you had an iPad and "it was fine", you actually spent $199 (or $249 for the 32G) more than you needed to.
Cost of an iPad + Cost of a Nexus 7 > Cost of a Nexus 7 alone.
But if you like it and another $199 is worth what you wanted, who am I to judge?
Even if a Nexus is better, I see no need to buy another device to replace one that is working well. If and when my iPad dies, then the Nexus is a very viable replacement and the cost difference is a good consideration. But $199 buys a lot of other stuff if I don't need a replacement for something that fits my needs.
OTOH, if pilots were financially astute, they wouldn't be pilots in the first place
Cheers