My son is of 3 months and I always choose bigger size, as I think, for him It will be more comfortable, to wear loose size.
I prefer tape diapers than pant style, because you can adjust band as per your need. Pant style diaper's waist band gives marks on my son's waist. Currently I am using pampers active baby's small size which is for 3 to 8 kg. It is very light weight and soft, not overly fragranced. 2 3 times I have find leakage but it can possible due to not sticking tape properly. I also bought Huggies dry tape diapers of M size, to give a try to this brand. This is also good product. It is thicker than pampers active baby, strong fragranced. Till date I haven't faced leakage issue.
After using both brands:
I will prefer pampers as it is lighter than Huggies.
I have not found any difference in size of pamper's S and Huggies's M.
Pampers is not fragranced and Huggies is strong fragranced, which is a point for me, opinions can vary person to person. Pictures are attached for reference.