Aikido, like other arts, is not a stand alone subject one size fits all.
Personally, i find that cross training to be complemetary.
Like having a right and a left hand.
One hand is quite good.
And you may get excellent dexterity with that hand.
But learning to use both hands together, or even the other hand, can bring depth and new perspective.
So wether it be training in a different Dojo, a different art, or a completely different field (like playing the flute or snow skiing or whatever) if you want to, you will find what you tell your self to seek.
As for open mindedness, I suspect theres another new thread, likely to be self congratulatory.