First I ordered these in all black (because the cute purple ones weren't available in anything close to my size.)  My street shoe size is almost always an 8.5, though a few brands vary up or down a half size.  Using the provided Sansha size chart, I ordered a size 10 (which says ladies 8.5), and it was too small--just snug enough that I couldn't have tolerated dancing in them long enough to try to break them in.  I returned those and went ahead the same day and ordered the red ones in the next size up (because by then the black ones were also sold out.)  I really needed shoes with some slide for my new Zumba workouts, which are impossible in my Sketchers and awkward (and uncomfortable) in bare feet.  The box arrived right on time--smelling like mold and containing raggedy-looking men's bedroom slippers in a torn and dirty plastic bag with the Sansha logo.  As always, Amazon was quick to set it right and process a refund--and inform me that the red ones are now also sold out.  So I still have no dance shoes.  I've looked on several different sites for these shoes, and each site gives different sizing advice--everything from "true to size" to "order 3 sizes up from street shoe."  Other, nearly identical, Sansha styles give completely different sizing instructions, and the reviews are all over the place in regards to fit. Since all their sizing charts are different for similar styles from the same company, I feel like I can't trust any of them--and I'm loathe to keep guessing and having to go through the hassle of repeated returns.

Strictly speaking of the product itself, I think they're decent little shoes (the actual ones that I ordered, not the nasty men's slippers) that would suit my needs.  The suede sole pad gives a nice balance between slide and stability.  They are an attractive style, lightweight; if I could get the right shoes in the right size I'd be happy with them.  These must be very popular, because the most common sizes are sold out on pretty much every site I've been to--except the ones charging more than twice the average retail price.  Unfortunately the sizing inconsistencies (and the smelly man-shoes) have made this a very frustrating experience.

UPDATE 6/13/11:  I found these on another site, available only in black.  They're actually a little less, but shipping is slightly higher, so it balances out.  Of all the shoes I've tried, these are working the best for me for Zumba.  They slide enough to give you fluid movement without making you slip and strain to keep your balance.  I ended up needing size 11 (I wear an 8.5 street shoe.)  The 11 fits without socks, or with thin socks.  If you like to wear thick socks, you'll probably need to go up even one more size.  Hope this helps.