^I would argue that the Nimzo-Indian is arguably the #1 best opening for black at pretty much any level of play.
The positions are strategically rich, yet can be tactical, and both sides can force lines in which all 3 results are fully possible.
It is also extremely solid, and even if you don't know theory, you won't lose, but instead just get a slightly worse position.
Also, if you don't like positional situations, then you should play them to get better! Assuming you want to improve. The Nimzo isn't actually THAT positional; there are plenty of tactics involved.
At the level of 1700s, where a player generally makes a silly, unforced blunder at least once every two games (observing a lot of 1700 players), the Botvinnik Slav is suicide, whereas the Nimzo is perfect.
I have played the Nimzo in OTB for my entire short chess career, and it has never failed to give me great positions.
Why don't you learn the queen's Indian Defense or the Nimzo Indian? Mr. Logozar.
Too positional, I don't like the types of positions very much. It seems much harder to play for a win.