Earlier on this thread DownupDave mentioned how some chose based on looks, others on sound. I'm of the later group and chose based on sound. Looks would be a bonus for the top board. Although the back and sides looks enters the picture.
I used to feel that Spruce and Maple were too bright. I had preferred the deeper, mellow sounds. I didn't fully appreciate sound demos playing up the neck. I only wanted to hear the deepest tones possible from a uke. Thankfully my tastes have grown. And I really appreciate when an instrument can play up the neck and continue to demonstrate sustain, intonation, etc..