If you buy the Ergo from the Mothers Direct site you should find that they sell it for a lot less than other websites (haven't seen it in other shops, though) - $140 odd at Mothers Direct, I've seen it other places online for about $170 odd.
Also, Ergo does wipe clean easily (I've got a black one, too!!) and you shouldn't wash it in the machine too often, but it keeps clean otherwise.
it should feel like you have a utility belt to use - strap it around your waist, get kid in frog-legged, bring armstraps up, do up the neck strap and you're done. The back position seems tricky at first, but is surprisingly easy to get the hang of after not very long at all! If you get it and can't find the instruction PDF, let me know and I'll email it to you, Ali
The only thing that bugs me about the Ergo is that it looks awkward if you want to wear anything over it because of the shoulder straps. With teh HAB you can wear a jacket or cardi over it and everything sits flat. Not an issue in hot weather, though.
I can still feed Oscar while he's inside the Ergo - something I couldn't do with the HAB because my boobs were too big. I just let out the arm straps but keep the neck strap done up. It's also far less daunting for a grandparent to use - my parents are both anxiety and stress-ridden - and they use it no probs!