I've used the in the swim wrapped sticks before. I was previously using Blue Wave from the local pool store at twice the price, and noticed no differnence other than that.

The last time I bought sticks I went back to Blue Wave because I found them on-line cheaper than in the swim, but I'm now 100% bleach for all things chlorine.

In the swim does huge volume. I'd be skeptical that the tabs you used were old.