I do know the new Danaher based line are pretty much identical to the Craftsman version.
(currently shipping) Danaher Kobalt sockets
(discontinued not currently shipping) Williams Kobalt sockets
Looks like you have figured out to ID them quickly; the lettering on the Danaher based sockets are read with "drive side down". Sounds like that is the ID factor!!!! I would skip the newer Kobalt; the pricing structure at Sears with their continuous sales are more aggressively priced and have sales more often IMHO. You didn't mention their ratchets but they are the same sucky design as most all of the Danaher ratchets; I'm not a fan and we rebuild at ton of them at Sears.
Quality wise I would assume they are similar to Craftsman which are both made by the same 1000 pound Gorilla, Danaher. With all things being equal; Sears has more choice, more mechanics tool sets, sales and cheaper prices.
Sears has discounts on their sets, sale and a discount if you spend over a certain amount of money.
Current sale and promotions:
http://www.sears.com/shc/s/c_10153_12605_Tools_Tool+Sets
There are better quality tools out there but for the price and selection it is hard to beat Craftsman; you might get a mechanics tool set from Sears and some Snapon ratchets or upgrade to the new thin profile pro ratchets or the old fine tooth models.
Craftsman 3 pc. Thin Profile Ratchet Set
Sears item# 00944992000 Mfr. model# 44992
Craftsman 1/2 in. Drive Ratchet, Fine Tooth
Sears item# 00944977000 Mfr. model# 44977