I have a Super C Shopper, bought 2nd hand about four years ago - I've used it regularly (1-2 times a week) ever since. I can definitely recommend it; the roll-top design swallows a good load, it's comfortable to carry off the bike, and it is easy to put it on and off the bike. I haven't had a problem with heel strike but the bike is either a Raven Tour or another tourer, and my feet are relatively small (size 5 / 38). There is quite a lot of adjustment in the carrier hooks and the bottom retaining hook.
I only have one so if I'm doing a large shop I pair it with a Super C rear pannier which I also have (my husband and I share a pair). It doesn't hold as much but I like the rear pocket for holding my wallet, keys and specs.