Sorry about brevity yesterday. WAs busy.
The manduca is great because it will last till your baby is a big hefty toddler and it is easier to adjust (between partners of differing sizes) put on and more comfortable for the baby and the parent.
I don't know the ins and outs of the BB Comfort Carrier what I do see though is that BB is copying carriers like the Ergo and the Manduca because it no longer has a monopoly on carriers in the main stream shops. Now it has to re-invent itself.
The Manduca is the best designed soft structured (buckle) carrier out there IMO. I have looked at a lot of them and have worn both children from birth. Now 5yo and 2yo) I carried my 5yo till she was 3+.