I think it would be well worth it. My DS is going to be 12 months in a week, and I've just bought a brand new Ellaroo mei tai. Best investment I've made in a long time!! Being able to carry him on my back at this age has made a huge difference. It's easier to get on and off than the HAB (which I also own and used a lot until DS was around 9 months old), and having him on my back means that I can do cooking, laundry, general tidying etc while I'm babywearing him. I'm using it every day, so I think it's well worth the investment!

An ergo would be a good choice too ... I chose the Ellaroo because I preferred the look of it, but in terms of function you'd probably achieve the same thing either way.