One of the things about Lend Lease aircraft that always got my attention is that they made very good use of the Bell P-39, they seemed to love it. The P-39 was originally designed as a high altitude bomber interceptor but early on in the design/development stage the turbo-supercharger was dropped and the resultant aircraft turned into a feebly powered lead brick much above 4000 m or 13000 ft.
The P-39 was so badly regarded by US pilots that on one occasion a local P-39 squadron was ordered away from base upon warning of a Japanese raid and told to let a P-40 unit deal with them. The a batch of LL intended for British use and with British radios, etc and a 20mm cannon replacing the 37mm was called the P-400. The joke that went the rounds was that a P-400 was a P-40 with a Zero (A6M) on its tail. Below 4000 m it could do a very decent job but above that it was a dog and too much Pacific and Mediterranian combat was above that altitude.
On the Eastern Front, most combat was at low level and the P-39 shined. Despite a myth that the 37mm armed P-39 was used for tank busting, it was not. The US supplied HE but almost no AP for the 37mm and anyway with the low velocity of the 37mm the AP round would have not been up to snuff. Against soft targets it was devastating. Against aircraft, despite its low muzzle velocity (2000 ft/s, 600 m/s), low rate of fire (150 r/m) and low ammo load (30 rounds) the 37mm could take out any aircraft with a single hit. Indeed Alexander Pokryshkin, a Soviet 59 kill plus 6 shared ace, did his best to avoid converting from the P-39 to later Soviet aircraft, he liked it so much. The Soviet judgement was that it was the equal to the Bf 109 and superior to the Fw 190 at low altitude.
Allowing for the limitations of any flight simulation, I have flown many Soviet aircraft in the IL-2 Sturmovik game. Like the I-16 the P-39 has a nasty habit of spinning but was very manoeuvrable at low to medium level. I still much prefer the Yak 3, an aircraft I would happily tackle a Zero with in a turning dogfight .