Summary: I bought 2 of these, lucky me. Number 1 has the connectivity issue. I traveled to my grandparents and it works great there. No extra signals or anything. Number 2 has the scroll issue, fine if you don't want to scroll. Needless to say I don't have either of these mice anymore.
Pros: It's a mouse with 4 buttons and it's wireless.
Cons: Has interference problems. It will not track properly in an area saturated with wireless signals. The scrolling does not work properly either, it tends to jump if you do a lot of scrolling. See other thoughts.
Excerpt: I use this product to edit photography. I like the design and way it feels on the hand. I'm disappointed because 1] the battery life is not very long 2] it does stop working whenever lint/dust collects around the window 3] the scroll up/down wheel stopped working not long after I bought it.
Summary: nice and compact for travel. extends to nearly full size mouse for use, which I like because mini mice just feel too small for my hands. I use it everyday and the batteries have to be replaced about every 4-5 months. $30 for a mouse for 4-5 years is a good deal in my opinion. I'm buying another.
Summary: It's not a bad unit. If it were $10-$15 less it would be an OK value. It's a mediocre mouse. It went back to my Logitech, but wish the Logitech tracked as well as the MS mouse.
Pros: It's a mouse. It works. Came with batteries. Tracks well. Light.
Cons: Feels cheap. The value of the fold close feature is questionable. It's still big. The USB receiver is HUGE. My Logitech units are tiny and don't snag on anything. Looks very easy to accidently break off. I have smaller thumb drives.