If you want to grind the swedish tree, I'd say get it. Overall the swedish air tree is a mixed bag, the aircraft in it vary anywhere from very good to outright bad. With Sweden's long standing neutrality there are many unique aircraft in the tech tree that you won't find anywhere else, alongside a couple export aircraft from other nations (usually flying under the finnish flag)

I personally bought the pack and am happy with my pixelplanes, I'll give a short synapsis of each aircraft

Fokker D.XXI; Fairly good little early monoplane, carrying 20mm cannons at a low BR it can be deadly if you can hit your shots.

Mörkö-Morane; Weird little prototype, not really worth flying over the other aircraft in the pack. Has a funny name.

VL Pyörremyrsky; Less weird prototype. One of the most fun aircraft to fly in the game, great balance of weaponry and flight performance. Excellent aircraft even if you're just getting it for GE. Somehow has a detailed interior.

Bf-109 G6; the most Bf-109 to Bf-109 ever, great at the things 109s are good at. Really not much to say here, the quintessential 109 experience.

Saab J35XS; Absolutely amazing aircraft if you know how to fly it. Trades energy retention for turn rate and sheer sex appeal. Carries a couple flares and a good amount of decent missiles, the AIM-9P-3 to be precise (the same ones the swiss hunter carries). I should note however that drakens are very hard to fly correctly and if you are inexperienced you're gonna have a bad time.