I found bg newborns the smaller (so fit better from birth), I found teenyfits a bit bulky on Aaliyah from birth (8lb 13oz). However she could outpee the BG newborn in an hour within a week so we got very little use out of them whereas the teenyfits are still being used now (boosted with a ll bamboo and a small hemp booster but she is a very heavy wetter). If nobody else can during the day I can take photos of the 2 side by side for you later this afternoon when we get home x
Bg fit better from birth, Oscar was 6lb 13oz and I found the teenyfit bulkier. I don't like the Aplix on these, far to big for such a small nappy compared to the BG tabs. O has just about outgrown the BG now, whereas the teenyfits are still going but I do have to boost both, I use a small bambooty booster. Saying that I don't know what the new V3 teenyfits are like with the new minky
I would have preferred to use xs BG but it isn't worth it for the small amount of time they last. I got mine free from Bounty mag.
I used BG newborn AIO with DD and loved them, but she outgrew the rise in about 10 days (she was 8lb 1oz born but long). I didn't buy BG this time (we hired last time) as I was expecting DS to be bigger, but he was a skinny long thing (7lb 11oz born) so the teenyfits were massive on him. They don't fit small enough around his skinny legs so I am selling them on. The BG smalls fit nicely though and have a pocket for boosting unlike the XS.
We used both from birth. The BG were slimmer fitting but not as absorbant as Teenyfits (boosted with a LL). She outgrew the BGs before outgrowing the Teenyfits. I think the Teenyfits were supposed to last til 12lb but they were too small way before that with her chunky thighs. I think the BGs were better for the cord. Overall I preferred the Teenyfits but I think it would really depend on the size/shape of your baby. I'm glad we had a mixture of both. (all sold on Classifieds too so if you found you preferred one over the other you could probably sell/swap them).