I have an iPad 1 and 2 and want to see whether anyone else with both has noticed similar circumstances:
Even on the same wifi network, my iPad 1 is "spinning" more, trying to hold onto or to establish a connection, compared with my iPad 2. I've noticed this during the past week, after moving. Before moving, there was no noticeable difference.
I have two wifi networks set up, so I can alternate, but the iPad 1 struggles on both of them, while the iPad 2 works fine. I've tried having the iPad 1 "forget" both networks, then reconnecting. I've also rebooted my router.
I also found that my iPad 1 sees fewer wifi networks (mine and my neighbors') than my iPad 2.
My iPod touch 4 and iPhone 4 are having no problems on either of my wifi networks. I even tested an old iPhone 3, and it's not having problems on either network. Stumped.