steggers,
The aircraft are very similar but for a few differences not limited to the following:
Archer is approx. 150 Kg heavier, has slightly superior performance stats (due to an extra 20 horses) such as a 5 kt greater max speed (133kt), a 50fpm greater rate of climb (692fpm) and a 3000 ft greater service ceiling (14000ft). It is also two inches longer than the Warrior (all other dimensions identical).
The Archer I flew had the switches panel (battery, alternator, magnetos, lights, etc) above the windscreen as opposed to on the main instrument panel, but this isn't the case with all Archers.
Regards
VC10 Rib22