Hi Taino, Der T.
Longer does not -necessarily- means better.
But sometimes it does help to have a longer harmonica so you can play through more octaves.
That is why I love my Chromatic Hohner 270, the same style that Larry Adler, Toets Tielemans and Stevie Wonder use. After the drums, the harmonica's are my next favorite thing. I have close to thirty of them, in various styles and keys.
I do play them while drumming, being it a simple beat, which makes one respect drummer/singers like Don Henley and Karen Carpenter because it for sure aint easy!
Cheers and Happy Drumming,
Harry