Oh, I'm not sure I would trade. I would keep the 500 until you've bonded with a new one. It's more work and $ in the air to sell a bike after buying a new one but there's fewer regrets. You seem serious about liking the bike you're riding and it'd be awful to " 'wish I hadn't done it! ". especially so when buying used...
I've never had a Connie but they seem ok from people that have (excepting fairing removal when needed-that seems a pest that I've witnessed) ... a bit more mass is not a bad thing on the freak-way to go along with a bit more gumption and 1000cc is not going to be 2x500, it also has to move the extra mass and the shaft drives generally eat power too...so I'm
guessing it'd just feel like a bigger more-planted Ninja...
But I'm noway recommending it-it's just that I mull them over for similar reasons as yours when I see them for sale...so it's really about me

the Hondas ducatiman mentions are another page I like to look at...