The main difference between the two cars is how they feel to drive, chassis flex and car weight are very open subjects and normally end up in a big thread where everyone agrees to disagree
In my experience the carbon parts make the car feel a lot sharper and are more consistent through bumps but the car seems to generate less, albeit more consistent steering.
A plastic car will feel more 'hovercraft like' and react slower and can be a bit inconsistent on very rutted surfaces. Plastic does seem to generate more steering for whatever reason, but it can be inconsistent.
A lot of people do seem to prefer the way the floppy; sorry plastic chassis feels though
You will go just as fast with a Team spec car as you would with a FT. If you're concerned about the weight difference you can more than make up for it by running older cells like 3300's instead of the latest 4200+ mah cells that are a lot heavier, if you're running stock you should have no trouble lasting.