The carrier: We bought the Performance carrier for our children (now 2 and 4 months old) about a year ago, before the model was available in the UK. As the original, it is an excellent sling that supports babies and toddlers well on the front as well as the back. The straps are padded and of quality similar to that found in good 60+ litre backpacks. Getting the babies in and out is straightforward but does require some degree of flexibility in the shoulders to fasten it behind the neck for front carrying. The hip straps suit both men and women and the shoulder straps are easily adjustable. The carrier is not bulky and will fit under a raincoat. I have carried my 4 month old 6 hours in a day in this sling without any problems and it's ideal for hand-free activites and light outdoor hikes. It's great for airport, train, and ferry travel. The shoulder straps do not preclude the use of a handbag, though the straps of the latter tend to slide down. For long hikes, although the Carrier itself is fine and ergonometric for the user, it doesn't have any storage for water bottles, etc. and you need a separate bag- don't bother with the one sold by ERGO as it isn't waterproof. We chose the Performance over the standard and sports model for several reasons, including that the Performance carrier has a pocket that the head rest can be packed away in as well as a side pocket that fits things 10-15 cm long (it's not deep, though, but passports will fit). For those who care, it doesn't have the 'organic' look of the original, but is still softer than the Sports model.
Limitations: For babies up to 4-6 months, you need the baby insert as the head isn't supported. This adds to the price and the baby gets too hot in the carrier on warm days (e.g. British summer). Furthermore, we found that our baby's head tended to placed into our chest rather than sideways (as it is in the Close sling). This might seem irrelevant, but when you are trying to sooth a baby with your finger or a dummy, it isn't. So, if you are considering using this for a high-need newborn, this carrier may not be ideal. Finally, newborns should be in a horizontal position and this sling does not provide that option. It also does not provide the possibility of an outward facing position. Of the many slings (more than 6) we have tested and used, the Close sling is better for the baby as it provides both of these options(although slightly trickier to get to grips with for the parents) compared to the ERGO carrier for babies up to 6-9 months. From then, however, the Ergo carrier is far the best on the market for house activities and lighter outdoor ones. For longer hikes, proper backpack carriers with storage capacity are better.