One difference is they seem to have gotten up and running faster...made a bigger splash out of the gate. Not as much of this "switch the format and then we'll figure out what we're doing."
Still not the full blown we're ready to roll but a bit better. Kind of like a restraunt opening before knowing what the menu would be or with no waiters. Could you imagine a new McDonald's opening with a notice on the menu board saying "we'll have meat on your sandwich sometime in the future...but here try the bun for now.
Keep in mind that WCBS was running their oldies format on their HD-2 channel, so they already had music in place, they only needed to add live jocks & such to get going. Oddly, I believe the WCBS PD Brian Thomas used to program 99.7 KFRC.