This nothing new, speed skaters have used something similar for years for dry land and summer training. While it may seem the roll up aspect has advantages it may also have built in disadvantages. Here are some comments on the product from speed skaters. www.skatelogforum.com/forums/showthread.ph
You can also build your own for under $40.00. I adjusted the price from that in the article to take into count inflation and local variances. msaskating.tripod.com/slide.htm
Not as compact and portable but well under 20% of the cost of the roll up one. You might even be able to find the plastic to make one.