Both the factory team b4 and team version now have a plastic chassis as they are much nicer to drive with them, with a the graphite chassis the car was very twitchy and difficult to drive so the change to plastic chassis is great
for the extra £35 or so it is well worth getting the FT B4 with the better shosk shafts and bearings etc. also the ti turnbuckles as i used to bend the steel ones from the team version quite easily and never had a problem with the ti's from the FT B4, also the front alloy hinge pin brace you get with the FT b4 is a must! toughens the up alot compared to the plastic one you get with the team version, for the extra stuff you get with the FT B4 it is very worth it!
With the team version you would probably find yourself buying some of the FT upgrades which would most likely end up costing you alot more than the extra £35 for all the upgrades the FT car has.
Hope this helps
Mike