I bought a box at Target - some stores have them on the shelves. I am a bit disappointed in P&G - they really seem to have missed the mark.
First, these are not nearly as absorbent as a similarly sized Pampers diaper. Secondly, they have an impermeable backsheet; they cannot be doubled up without cutting the backsheet to allow drainage. For use as a booster, I've done this and while they certainly do improve the capacity of the primary diaper, as mentioned, a regular Pampers would do better.
Finally, their cost is bordering the ridiculous. P&G pricing on these, a less capable product, at about 50¢ each, is just excessive.
For comparison, prices for other products (varies on package size, vendor, and market):
Pampers Pure Diapers (Size 4).....40¢
Pampers Swaddlers (Size 4).........36¢
Pampers Baby Dry (Size 4)...........29¢
Pampers Cruisers (Size 4).............39¢
@DailyDi is spot on - this product line doesn't seem destined for longevity unless P&G re-imagines their implementation...