I doubt it was much of a turn and burn ac, given the wing loading of 40-60 lbf/sf empty/full. Consider the 410 as a comp at more like 37 on the empty side - itself no yank and bank bird. OTOH, given the armament, it'd probably be a nice bomber hunter. It's also possible, given this Arado "traveling flap" thingie, that you could significantly improve your low speed turn performance by deploying the thing. Apparently, they were shooting for low profile drag at the expense of having to use a higher CL (and consequently induced drag - goes like CL^2/AR).
Still, a cool bird - and one that saw service.
<snip from wiki>
Technical specifications were first published in October 1938, followed by detailed plans later that year. In May 1939, the RLM ordered a batch of six prototypes. The first Ar 240 V1 prototype, DD+QL, took to the air on 25 June 1940, and immediately proved to have poor handling in all axes, and it also tended to overheat during taxiing.
The handling was thought to be the result of the ailerons being too small given the thick wing, so the second prototype was modified to have larger ones, as well as additional vertical fin area on the dive brakes to reduce yaw. In addition small radiators were added to the gear legs to improve cooling at low speeds, when the gear would normally be opened. Ar 240 V2, KK+CD, first flew on 6 April 1941, and spent most of its life at the factory as a test plane.
Ar 240 V3 followed, the first to be equipped with the FA 9 rear-firing armament system, developed jointly by Arado and DVL, armed with a 7.92 mm (.312 in) MG 81Z machine gun. Ar 240 V4 was the first to include an operational dive brake, and flew on 19 June 1941. Ar 240 V5 and V6 followed in December and January, including the upgraded FA 13 system using two 13 mm (.51 in) MG 131 machine guns in place of the MG 81Z for a considerable boost in firepower.
The Ar 240's excellent performance quickly led to the V3, V5 and V6 being stripped of their armament, including the defensive guns, and used as reconnaissance aircraft over England, where no other two-seater could venture by 1942.