I've had one for a long time. We keep a cantilever on the hybrid, but my Saturday-go-to-market bike has a Topeak rack that mounts with 3 contact points (like your link).

Like ridenread I have a basket attachment for the market that works great. Best investment I made for that bike.

DH uses a rack bag with panniers on his. Needless to say, I get to carry the bigger and bulkier items.

If you have room for the basket attachment, it is more versatile for groceries. I was using bungie cords over the top, but then DH found some Blackburn "nets"--elastic with 4 attachment points. Makes things even more convenient.