I have just acquired this interesting device. Have only used it for 3 nights, but so far the data looks impressive. It measures/monitors your sleep wirelessly and in conjunction with your smart phone delivers a report showing the amount of light, deep and REM sleep as well as wake-ups (arousals). Will report more later, but thought it might be interesting to start a thread and share if others are starting to use this. Not going to do a product description - you can get that from their website.
This is interesting to me as well and I'll look forward to your review. I googled "s+ resmed reviews" and found several independent reviews but each had a commercial link in the review so I won't post them here. The reviews made the S+ sound promising with their pros and cons listed.