Hi, I use the Ergo carrier with my seven month old, 20 pound ds and I really like it. I had spinal fusion surgery and so I have a lot of back pain but I find the Ergo to be great. I prefer using it with him on my back. If you adjust it right, it is comfortable and I can wear it for a long time. I would love to figure out a way to carry ds on my hips too, someone said it is possible with the Ergo but I do not know how. Anyway, I recommend the Ergo and I believe there is a thirty day trial period where if you find you do not like it, you can send it back for a refund. Good luck!
You can get Ergocarriers for a discount if you buy in bulk. I got mine for $20 off when a woman on another board took orders from other people on the board and then bought a bulk shipment. I can't say how good the ergocarrier is because I haven't used it yet. One problem: I am not a fan of the color selection for ergo carriers. I know that's a silly thing compared to comfort, but I wear my baby carriers so much that I want them to be cute.