MXL V67 vs. crappy Shure SM48?

With the theory that it will make my final mixes better and easier, I've been trying to put more of an effort in to pay close attention to the sound quality of my recordings. As I recorded vocals for a song yesterday I experimented with my two microphones. I posted a question about this to the home recording BBS:

I own both of these microphones. I bought them when I knew absolutely nothing about recording (I know only slightly more now). I'm running them both through my Mackie 1202 VLZ and am monitoring on Event 20/20bas monitors.

When I record my voice using them, I swear I prefer the sound of my cheap Shure SM48 over the vastly more expensive and critically acclaimed MXL V67.

The V67 sounds a bit fuller but at the same time kind of muddier and it's harder getting it to sit in a mix properly.

Is this possible or am I just crazy? Maybe my voice is naturally muddy or something.

I received a lot of helpful replies which you can read over there if you're so inclined.

Bradtech