I also agree. It will take you a little longer, but the difference is worth the distance. Additionally, study the relationship between the keys. A lot of the chords that you use translate to other keys in a different way. For instance, I use the following chords as a transition in 3 keys:
lh/rh
C,E,G,Bb/Db,Gb,Bb
C,Eb,F,A/Eb,Ab,C
Bb,Eb,F,Ab/Eb,F,Ab,Db
In Ab, it's transition from the VI to the II
In Db, it's transition from the I to the VI and...
In Gb, it's transition from the I to the III
There are countless examples of this. I hope that helps.