Danni, I have a pocket sling (with rings) which I love. But I think you'll find it similar to your HAB, in that it takes a bit of practice to get it right (although if you always remember to put the baby's bottom on the seam it's pretty easy). Also I don't think Mason could go forward facing in it any earlier than he could in the HAB.
But like Brooke and her HAB, I'd never have been able to shop until Tom was about 6 months without it.