i do not know if i wrote on this thread before.
our preference is for our DS to be rather free-roaming when walking. for the most part, we simply walk closely to him and observe his surroundings when he explores. he can take off, but we are usually right there to grab him before he gets too far, or near something too dangerous for him.
when we are in crowded spaces, we are more likely to hold him or ask him to hold hands. he can still draw his hand away and take off, so we are cautious in crowds overall. i tend to avoid them myself.
likewise, we take him on city walks. a few afternoons a week, DH takes DS on city walks. they hold hands while walking on the side walks and he gets carried across the streets. he walks on the inside (away from the road side) and does well overall. he is learning the basics of city-street walking.
he is happy in carriers as well.
there are a few times when the leash has been valuable.
1. my father broke both of his feet (17 breaks in one, and 21 or so in the other), and so his feet hurt quite a bit even though they are fixed. he can walk on them, albeit slowly.
my father loves to walk with DS, btu DS is still unpredictable enough to take off and head towards something dangerous. my dad cannot keep up with him or after him. so, when my father wants to be with DS, we put the leash on him (monkey back pack).
in particular, my family and I would go to crowded places togehter as well--so the mall at a sale time, or to the botanical gardens during the christmas time--and so on top of not being able to keep up with unpredictability, i also wanted he and DS to be close together as the leash would allow.
on such occasion, women have made comments. every person who did had their child in a stroller. to which i asserted "is it more or less problematic than having a child strapped into a wheeled chair?" honestly, a stroller is useful in many ways, but i believe it is overused, and that often used to control a child rather than simply to provide respite to child or adult (if the adult can't babywear for example). often, it is simply a means of control.
at least, the leash allows the child freedom of movement to explore.
2. when we moved from US to NZ, we had 8 large bags. i had the baby on the leash because he would not be worn that AM--we were all to keyed up.
it was helpful to me because i knew that he would be within a safe distance, and that it would be unlikely that he would be carried off, get lost, etc, and it made it easier to manage the tickets, the bags, security, etc etc etc while travelling.
once we were at the gate (bags checked, through security, etc) one would stay with the carry ons while the other pottied the baby, then we would switch (one going to get food or what have you), and then when both of us were settled, one would walk/play with the baby in the waiting area while the other read/rested. and we took turns.
because of our process, we had to go through security many times, and so once getting off a plane, we would have to transfer from domestic to itnernational flight, for example, going through security to get on that flight, and then once in NZ, getting off one flight and transfering to domestic--going through pass port control, inspection of our items, etc, and then back through security for the domestic flights.
so, i think we went through security about 6 times just to get here, and it was helpful to have hands free when he would nto be wrapped (also security didn't want him wrapped so that they could check us thoroughly).
otherwise, it is just a stuffed toy to him (i remove the leash when we are at home, because it is jsut a choking hazard IMO), and he loves his "monkey baby" and plays with it often. he also likes t attach it to his back pack (one of the carriers we use) so that his baby can also go for a ride).