I bought one and think it is pretty good value, it covers the area of about 15 Michelin maps and is of good quality.
Last year I just took the pages I need for where we were going, the scale is not as detailed as Michelin but as I had sat-nav and the map was really a "backup" this was of no concern.
The list of Hotels and bike shops on the back of each page is a very nice touch, the other thing I like is the size and construction, they easily fit into tank bag pockets and the waterproff construction means no problems with them turning soggy.
I also put all my routes on using a dry-wipe marker pen and then cleaned them off when I got home.
If you plan on going back to various areas it will probably pay for itself, same goes if you break down and it helps you instantly locate a nearby bike shop that deals with your motorcycle brand.
The area goes beyond the Alps by some way, the Black Forest area is also covered.
but, is it worth it? 
Might have to invest in one of those
