SCAL5's rhinestone feature is definitely better than MTC's for the following reasons:
(1) It does do a better job of having the right and left sides match.
(2) It doesn't lag if you need to break apart the design and edit.
(3) It has rhinestone simulations so that you can more easily see what your design will look like.
(4) If you resize the design AFTER applying the rhinestone effect, it will automatically adjust the number of stones to keep the same spacing.
You can download a 15 day trial version of SCAL5 if you want to test it out yourself.
http://www.craftedge.com/download/download.htmlFeel free to post more questions about SCAL5.

And, naturally, since you have a KNK cutter I will gladly help you with any questions regarding using your model with SCAL. Also, I have KNK user manuals that now include SCAL on my site.