Lineform
http://www.freeverse.com/apps/app/?id=6020
© 1994-2008 Freeverse, All Rights Reserved.
$79.95
Lineform is a super cool vector editing tool. It makes Illustrator look like the most bloated app ever. And SVG is one of the formats it supports most heavily. I did have to export them from the native filetype, but the exports were very clean.
Migration Score
GOOD
Migration Options
Inkscape
Inkscape works with SVG directly so it's pretty easy to just pick up the exported files and get moving.