I have a carbon mast on my Uni and love it. It's easy to step and right. It doesn't hobby horse and it's light. Negatives include difficulty to depower and shape sail. I would definately do it again, however I might not if I had to pay additional $$ to replace an aluminum mast that was still working. You have stated what I say to myself many times when thinking of getting new "stuff" and that is that if I want to go faster, I can first learn how to sail better. Most of us have much room for improvement.
<br>
<br>However, if it is for comfort or safety (and you get a little faster), go for it. This "stuff" is cheap compared to some hobbies (rationalization if you need it).<br><br>