BH Mei Tais are lovely and soft esp if already broken in. I think they are good til about 12 months average baby size. I think they are a good MT to begin back carrying. My DD didn't like the ergo either until she was about 8 months. I got a manduca this time around but I haven't started DS in it on my back as he is still a bit floppy. I find front carrying a floppy almost 9kg baby hard work and don't get much done while he's in it except helping DD to the toilet :/