I’m soon unlocking rank 7 of Swedish tech tree and which plane should I go for :)
Dorito(aka the entire rank 7)
I would generally categorize the planes like the above image.
The leftmost line is good, but the draken could be a little difficult since it lacks flares at a high battle rating. If you know which planes carry dangerous missiles you can perform quite well in the draken though. JA37C is an absolutely wonderful plane with good radar missiles and an unbeatable radar at 11.3, almost guaranteed 2 kills per game. The stock grind without radar missiles can be a bit difficult though.
The middle line does not contain anything great, the planes are good, but they are too limited by pylon slots. You have to sacrifice guns, flares, or missiles, you cant get everything at once.
The rightmost line only contains the Mig-21bis which is an all-around good plane in all respects. It is neither overpowered nor bad. The engine is great and you can turn fast if need be, with a decent missile load. That makes this plane quite forgiving even if you make mistakes or miss missile shots.
I would recommend the Mig-21bis first, then go for the leftmost line for a generally enjoyable experience. You could then use the JA37C to grind rank 8. If you know what you’re doing then you can go straight for the leftmost line, but it may be a bumpier experience in the start.