I do agree that it is technically better than the Loc8tor that I use. But it is also about 3 times the price too.
I bought the Loc8tor about 3 years ago but didn't need to use it the last couple of years. If I had to choose all over again, it would be a tough choice to pay the difference in cost. The Loc8tor does work effectively but knowing the general area of the downed plane is helpful to put you within the range of the tag.
Having rechargeable lithium batteries in the Marco Polo is a real advantage (if you keep them charged). The Loc8tor tags specify Silver Oxide batteries which are not carried by most stores. So batteries will last over 5 years without use so it is wise to remove them from the tags in the off-season. Alkaline batteries are a cheaper reasonable alternative (as per Frank F) if replaced yearly.
Loc8tor is available on eBay, Amazon, and directly from Loc8tor.com
http://www.loc8tor.com/everyday/loc8tor-lite.html/#Overview. The Lite version is currently US$80.93 + $7.53 shipping.
On reflection, I'll stick with the Loc8tor!