Angel,
Bjorn' con is that it can only hold up to 12kg unless if u get synergy/active. Think original/air up to 10kg. It is one of the best n popular choice for newborn. Pikkolo hold a bigger bb from 3/4mth onwards till toddler. Pikkolo got nicer designs than ergo so i grab and price ok. Bjorn are more exp than ergo and pikkolo. Both can have front and out facing mummies, ergo only bb face mummies, cannt face out.
I think if use carrier, must go to air-condition/airy place with shade. That time i use a brandless carrier, took her to toa payoh hawker, seated near the outdoor, she is ok. If u are worried abt heat rash then prob hand carry or use sling/pouch. Then again sometimes bb r ok, sometimes not. My pikkolo coming these 2 days so i would try to pick up this weekend when hb comes back and try on her.
I intend to use my pouch and pikkolo on her when i am at home doing chores esp when she needs carrying almost every hour. Think bb likes to see the world now so they like to face out, when they r sleepy, they want to look at mum/dad and sleep, then face in. Same thing w pouch/sling.