Can't decide which Microphone to keep for vocals: Shure SM58 or Audix i5?

First of all, I would like to point out that I do NOT have much
experience or knowledge of microphones except what I have read over
the past 2 weeks from reviews and whatnot.

And I know most of you reading this are probably thinking im crazy for
asking this question and want to say "THE SHURE SM58 OF COURSE!!" but
there is just something I like about the Audix i5...

I recently bought the Audix i5 mic to use for recording both guitar
and vocals. After a few days I decided I really didn't need a mic for
guitar, and I thought I would swap out the Audix i5 for a mic made for
vocals (the Shure SM58). I went to my local store and got the SM58 and
brought it home to compare the two.
I was actually shocked because after reading so many excellent reviews
about the Shure SM58, I for some reason feel like I prefer the Audix
i5 mic over the sm58.

The main difference I hear in the Shure SM58 is that it gives me a
more clear and crisp sound, and it doesn't seem like it alters my
voice in any way. The Audix i5 is still pretty clear and crisp, but it
changes my voice, but I like the change. I can't sing stuff very high,
and when I use the Audix i5 I can go higher and it still sounds good,
but when I use the Shure sm58 I can't go as high and my voice breaks
up...
I wish I could explain it better, but I;'m just asking for opinions on
what I should do?

thanks :D