Re: tagalong vrs bike trailer??
I have a 4 yr old DD and we have a trailer. I agree w/ all the other PPers that w/ a trailer you can stuff stuff in there in addition to the child. I also like that DD can fall asleep in the trailer, can't do that in a tag along. : )
I bought mine used and may also resell when she gets too big for it.
Ours isn't fancy, we got it from CL and are quite pleased w/ it.