I have had a close carrier, baby bjorn, ergo, one from the ABA website can't remember what it was called and now a kathmandu carrier. I personally hated the close carrier I got too frustrated trying to use it DD would scream every time she got in it so I sold it on. We used the baby bjorn same thing DD hated it. The exxy one from the ABA website I liked it and DD loved it after a while. My ergo, I tried to use it but I just couldn't get her in it on my back so gave up, and I am eager to sell it. Now we use the Kathmandu one. For me and DH its a dream. I ahve a bad back, 2 bad knees and a bad ankle and this seems to be the only carrier that has helped spread the weight load around.
I cannot BF in it and it couldn't be used for a real littlie with no neck strength but its so convenient because if we go out I can pack all of DD stuff in the under seat compartment. As its designed as a backpack I haven't found it too hot to wear but we are also not in summer yet

HTH a little bit
Nae x