Which do you believe creates the best sound or can you create the best sound by using them both on the same drum?

Depends on the sound you are going for, the size of the line for which you're using it, the venue, skill level of the players who will be playing on it, etc.

In general, I like a Kevlar bottom tuned as high as you can get it (top head slightly lower than the bottom) with a patch and no tape, simply because I like for the drum to actually sound like a snare drum - not a raspy-sounding table top or slab of cement.

Patch? Like an old school wad of tissues taped against the head?!

I personally like the drum to breathe and give off it's natural timbre characteristics. I do place one small piece of stick tape across the guts in the center of the head to help shorten the buzz just a bit. It gives the drum a little bit of a pop and better clarity. I don't tend to tune as high as some high schools and not anywhere near 'table top' drum corps tunings. I don't think it's good for the ears, or for the wrists.

One thing that I've always been successful with was tuning the guts up, then to use a little strip of tape just long enough to go over all snares. I personally like to have very little tape-to-head contact.

Also, if your working for a line with not a lot of money (who isn't?), and your not endorsed by remo, I would suggest the Evans hybrid tops & bottoms. At my high school, we've used the hybrid bottoms for two seasons w/o changing and they sound great. They really hold their tune very nicely. With the tops, we've been more successful with the gray/black tops. Every time we've used the white tops, we've let the head seed and then when playing the head separates from the hoop and your SOL.

Hybrid Bottoms with no tape are very reliable and don' sound too shabby