We loved the moby with our son who was 5 lb 8 oz when we took him home. I would wear up upright in the moby, snuggled against my chest, almost all the time. He slept really well and it was dark and cozy enough in there that he did not get too overstimluated.
Also, the moby works pretty well with just a nursing tank top, almost looks like a cool shirt. Sort of kangaroo care on the go.
You will get alot of attention from people wondering what in the world you have in your shirt when you go out with a tiny baby, though!