May I suggest that you have a think about what features you want from a carrier - what is most important to you? Realistically, there is no one carrier that suits all people, and that performs all functions. Different carriers also suit different body types/sizes, so what suits an average sized mum may not suit a very petite mum (the Ergo can be a very good example of this, as can many of the padded buckle slings like Bubba Moe and Baby Rock). Anything that is 'shaped' will suit particular body types better than others. Within each genre of carriers, eg: ring sling, mei tai, SSC, there are any number of different brands, each with their own specific design and shape, so if one does not suit you, another might.

To answer some of your points:

- safety: what exactly do you think of when you ask about safety? To be safe, a carrier should fit well and be well made with no flaws in the construction. Potentially though, any type of carrier has the potential to be safe or unsafe.

- comfort: overwhelmingly, a wrap (stretchy or woven for newborn, woven for older babies), is the most comfortable type of carrier, as it is infinitely flexible and adjustable. This is especially true for wearing for long periods of time, pressure points can be more easily avoided in a good wrap. However, a wrap has the steepest learning curve and is not as quick to put on as other carriers. Mei tais are another good alternative if you cannot find a SSC that works well for you - quicker to put on than wraps, but more adjustable than an SSC. Generally speaking, two shouldered carriers will be more comfortable than one shouldered carriers, especially for long wears and for carrying older children.

- ease of getting in and out: pouches, SSCs (soft structured carriers) and ring slings are the easiest carriers to get baby in and out of, although there are some wrap carries that can be pretied for easy in and out. (Pouches are not a good carrier if more than one person intends to wear them - they are sized to the wearer and non adjustable)

- breast feeding: adjustability is key for easy breastfeeding. A ring sling is usually considered the easiest sling to feed in, as baby can either be in a cradle position or vertically. Unlike a pouch, it can be adjusted to bring baby closer to your breast. For babies who like to be vertical, a mei tai is more easily adjusted than a SSC.

- ease of movement. Many people find that a wrap allows for the most ease of movement, as it can be worn in a number of positions from newborn (even back carries), unlike most SSCs. An Ergo can only be used in a front carry with the infant insert from newborn, as can most other SSCS (Pikkolos are an exception to this, as the seat can be cinched in).

I have given more of a general overview rather than any specific advice, if you can give us more information - what attributes are most important to you in a carrier, and what size (height / build) you are, then a choice can be narrowed down. It's also worth remembering that some carriers are specialists - ie: good for a particular circumstance (eg: stretchy wraps like HABs are great for newborn wearing but not as good for older babies, pouches are great for quick up and down carries but may not be comfortable for long wears), and others are more generalist. If you have very specific requirements you may consider getting more than one carrier (eg: a pouch or ring sling for quick up and down carries, an Ergo or other SSC for longer wears and for when they are older, or a good wrap).

HTH!