Some of the answers have touched upon convenience for the player, but have missed one point about this. In making arrangements band and orchestral arrangements, I have found that wind players often prefer sharps to flats, preferring for example 7 sharps over 5 flats. This is noticeable particularly with transposing instruments. String players, on the other hand, seem to prefer flat keys to sharp ones.

Equivalent Key Signatures
Out of necessity, I had to put an 1.26" (32mm) rear tyre on my bike where the front tyre is only 1.1" (28mm) wide (and the bike came with 1.1" tyres when I bought it). Are there any advantages or disadvantages of this, shall I try to get an 1.1" tyre for the rear wheel ASAP or is it safe this way?
