It is not a matter of which process is faster, it is more of which process is applicable. Submitting the I-485 with the I-130 is an option available to someone who was already in the US when the decision to file for AOS was made. Since you and your husband are currently outside the US, concurrently filing I-130 and the I-485 is not an applicable option for your. Your husband will not be submitting an I-485 at any point in time this case. You file the I-130, which upon approval gets sent to the applicable embassy, you husband will subsequently fill out and submit the DS260 form in order to get scheduled for his appointment back in Canada.