Its worth having. It is the first USAAF plane worth an ENY price of 5. First USAAF plane whose all-around abilities really put it somewhere near the league of the other nation's best LW fighters on the deck. The non-WEP advantage over the N really helps. Firepower, roll rate, some fairly decent turning ability, and dash of very fast speed. It is not in the league of Spit16, La7, possibly not even the D9 or K4, but it'll do.
Strange as this sounds to say about a Jug, I think it may become the USAAF plane used most for base defense. 25% and 267rpgs gives a full throttle time of 15 minutes with an initial climb rate of nearly 4,000 fpm, and not inconsiderable turn, plus the speed, roll, and firepower.