So-called 'recovery boots' are for the most part an additional sales channel for a product that has existed for decades: sequential circulator to treat
lymphedema. These supposedly medical-grade systems sell for thousands of $s, and require a prescription. By changing the range of available compression the prescription requirement is by-passed, and voila, a product for the masses exists. Most name-brand so-called recovery systems are an off-spring of a medical device parent: for Normatec Recovery, see
http://www.normatecusa.com/. For SportPump
http://www.sportpump.com/, see
http://biocompression.com/. Etc. Even visually, it's easy to see the similarities. The so-called 'recovery' system is merely a re-badged version of the medical one. Of course the manufacturers don't tell you that, and they also don't tell you that via e.g. craigslist you can find the medical version for pennies on the dollar.
For example, the SportPump SP4 pump retails on their site for $1199. Two leg sleeves will set you back another $300+ (depending on size). The medical version (BioCompression) does not list a price, from what I have seen they sell for 2x or more. Funny thing is, in my local craigslist I see a full BioCompression system (pump and two leg sleeves) for $240. They keep coming up, frequently and regularly. The difference? Branding, and the 'medical' version does not have any flashy logo with the term 'sport' in them.
A couple years ago when I became interested in these systems I called SportPump, chatted a while with a rep, and he basically told me that yes, they are selling technically identical and merely re-badged product.
Disclaimer: I am no medical professional or anywhere close, the above is based on personal research from a couple of years ago, and may or may not be considering all applicable details. That said, the BioCompression pump I bought for a couple hundred $$s off craigslist a couple years ago still pumps strong, and has the desired effect. YMMV.