Done both, found Instrument more challenging and has capitivated my attention long term by the desire to improve.
Found Aeros boring after the initial thrill was over. And it was even worse sitting and listening in the club to the endless ramblings of the self confessed aero experts who promptly passed out on an outside loop.
How we choose to "master" the aircraft is a personal choice.
Each to ther own.
And haven't we done this subject to death only a couple of weeks ago.