Options using IB's TWS platform, papertrading vs Realmoney

I've been papertrading using TD's ThinkorSwim (TOS) platform for the past few months. I have been getting fairly consistent profits recently and wanted to trade for real. However due to cost I'm shifting over to using IB's Trader Work Station(TWS) papertrading platform. I find the trades take a long time to fill and it is very difficult to get fills on closing trades. I'm using both platforms side-by-side concurrently. I find TOS I'm able to get fills more easily, while IB's platform is very difficult with the exact same positions. I was wondering is this just to due to the papertrading system or this is to be expected when trading real money as well? I always trade High Volume and Open interest 500+.