Even though the Code says that you can Romex the apartments and anything not in the drop ceiling. I would read the job specs. carefully and contact the local AHJ. to see if there are any local restrictions. There are places aroud here that want MC for commercial at the minimum. But down from where I live they did the condo's with commercial on the bottom and romexed them, they even used 14/2 for 15 amp. circuits in the residential part. But check it out before trying this, I know that other areas that would never go for that.