I have used the Sizzix products in scrapbooking for years and years. The company is wonderful for its products and for its service. The quilting sizzix is now being advertised in quilting magazines, so I'll bet the marketing strategy may have been to let "GO" blaze the trail and test the waters before jumping into the market. Personally, I'd stay with sizzix because I'd be able to use all my dies that I already have - BONUS! (there are also sizzlits dies but I don't think they'd be as good on fabric because they are so thin.
You can usually find the dies on eBay cheap.