Here is a list of the most important Allied aircrafts in Forgotten Battles including advantages and disadvantages:

I16 Typ 18/24:
A very maneuvrable and stable aircraft but relatively slow. Because there is no canopy the pilot is very prone to machinegun fire. In most russian planes you should only attack in turn fights and engage the enemy in thight maneuvres (turn-and-burn tactics). The axis planes will try to shoot you down by outclimbing you and then jumping onto you from above. Because of the low top-speed one cannot counter such attacks in most cases. Try to evade the enemy fire by jinking. If your opponent is experienced in energy-fighting you'll have a pretty hard time in this bird.
I153:
Although a bi-plane the I153 is a later design from Polikarpow than the I16. It is even slower but more maneuvrable. It only rarely stalls but it has only limited armour protection. The pilot is also very prone to enemy fire. Be very careful when chasing the enemy for your engine is very sensitive in negative-G turns and might evenl sometimes shut down itself. To prevent this watch your rpm and also listen carefully to your engine sound.

LaGG3:
Relatively average on everything. Early versions have a good armament and turn-rate while later variants are faster. The LaGG series has only mediocre armour protection and a bad climb-rate. Like all other VVS planes try to engage the enemy in turn-fights. The LaGG3-IT is equipped with a 37mm cannon in its nose whcih replaces the usual 20mm gun. This weapon is very effective against bombers but with a careful aim it can also be used to bring down fighters.
La5 (F/FN):
An evolution of the LaGG3 with a more powerful engine and a streamlined profile. Although early versions (La5 and La5F) were known for being sluggish and inferior to the more technically advanced German fighters of that time the La5FN became a great dogfighter and later one of the best russian-built planes of the war. The FN also had more armour than early versions.
La7:
This plane is basically an La5FN with different armament and some minor aerodynamic changes which speed up the plane. It is equipped either with 2 or 3 B20 cannons and superior to any other allied and axis plane in turn-fights.

Yak9 1942:
This is the first plane of the Yak-9 series of fighters. It's is an evolution of the earlier Yak1 and Yak7 aircrafts and surpasses them in almost every aspect. It is more maneuvrable than any of its russian competitors in 1942 but has a somewhat limited armament which consists of 1x12mm gun and 1x20mm cannon in its nose. Another disadvantage is that most of the plane is made out of wood and therefore cannot take much damage.
Yak9D:
The only difference worth mentioning is the longer fuselage which provides a bigger fuel capacity. Same armament and armour.
Yak9T:
The T version was intended as a tank-killer and equipped with a 45mm cannon in the nose. It is very good against static targets like ground objects or bombers but due to the massive recoil only single shots can be fired making it ineffective against highly maneuvrable targets (fighters).
Yak9K:
Same as the T but with a 37mm cannon instead of the 45mm.
Yak3:
The best of the Yak series planes equipped with 2x12mm guns and 1x20mm cannon. Highly maneuvrable and considerably fast. If you are flying an axis fighters (FW190, Bf109) stay out of any turn fights and make surprise attacks when possible. Energy-fight highly recommended!