chicks are time consuming. once they get a few weeks old they smell a lot more and they create dust. they try to fly pretty young so probably want a covered brooder. you tend to get pretty caught up in them and find yourself checking on them at three in the morning for no reason. when they do go out into the coop you practically camp out there with them for all the worrying you do. but you also get them from day one (or two or three) and you get to watch them grow and hold them and bond with them. it makes it harder to watch them establish their pecking order or to deal with animal attacks. it is always hard but it seems even more difficult when you raise them from chicks...imo.
with getting older birds you just never know...they could have underlying illnesses or a really bad temperament. you lose a lot of the bond you could have gotten with chicks but you do get eggs faster. if you have an existing flock then you have to quarantine the new birds for some time which can be difficult if you are not set up for it. pullets can come home and go out to the coop farily quickly so when deciding on chicks or pullets it really depends on your commitment...do you have the time for chicks? if not then pullets are a better option. can youhandle the birds inside for the better part of two months? if not then, again, pullets are the better option.