We really like our Ergo. It's very comfortable for carrying our 7 month old: her weight is distributed very evenly and it's really pleasant to carry her on the front or back.
Getting the baby into the carrier on your back takes a little practice. It can also be a bit awkward to fasten up the clips on the back when carrying baby on the front, though this could be due to the inflexibility in my shoulders! I haven't really needed the sleep hood much so far, but I have also found this a bit tricky to do up when baby is asleep on my back. We chose the new Ergo over the Patapum so we could also use it as a hip carrier, but haven't found it particularly useful for this purpose and have stuck to a ring sling for hip carrying. I've tried a friend's Patapum and to be honest it was almost exactly the same as the Ergo, though Patapum has a lot less padding. Hopefully the Ergo will remain comfortable as my babe gets heavier, which I felt the Patapum may not. Overall I think the Ergo is a really good carrier: sturdy, well made, comfortable, good looking and pretty good value for money if you carry your baby a lot and for long periods.