Once again, see
http://www.visajourney.com where I'm quite certain you will find dozens upon dozens of positive outcomes
sans lawyers. Personally, we started out with lawyers. The first one did absolutely nothing. Not a blessed thing. For 6 months she had our paperwork, then sent it back saying she was closing her practice. And no, she did not refund our money. The second one first sent all the paperwork to the wrong USCIS office. But I noticed when it was returned after rejected, that his office hadn't even copied the forms correctly from what we had given them.
NO ONE will care about your own case more than you will. All a lawyer is going to do is have you fill out the forms for them, and then they'll send it in. They'll take your money, but there's not really anything they can do for you that you can't do yourself. The only reason you *might* need a lawyer if either one of you has a criminal record that would require a waiver or additional paperwork of some sort.
No idea how a lawyer would be more cost effective, when most of them are going to charge you about $5000 for the privledge of slowing down the process for you.
It is VERY rare for a Can/Am couple to be denied a CR1. The only reason usually for denial is if the US half does not have enough income to support their new spouse. Or if one of them lies on a form somewhere and they are found out.
Go to VisaJourney. Lots of people there with horror stories about lawyers. And the majority of them, like me, end up firing the lawyer and doing it themselves.