I like the form and efficiency of space overall for its size. Seems a bit out of proportion to the existing house on the site.
Is there not a way to get from the south garage to the stairs for its corresponding unit? I would think you would want to stay inside once you parked your car.
Being as tight as the garages are, I would suggest impact or abrasion resistant drywall or even better yet 4' high FRP panel to protect. I know you can get this in the subway tile look as well so it doesn't seem so industrial/kitchen like.
The western units second floor seems to have a lot of circulation space/hall way that won't be usable for anything else. This is most notably between the island/stair and and dining area. Maybe consider putting the stairs to that unit in the southwest corner with an odd shaped landing/switch back and pushing your powder room/laundry to the west and then shoving your kitchen against the north wall. This will wreak havoc on the second floor but could make your second floor more functional. The furniture show doesn't allow any wall way around it as its shown now anyway. (see attached image - sorry its not the greatest). Also, don't put in area specific lighting like a chandelier. Can lights will work fine, and some one could use the dining space as a home office area instead.
I would closely at the drive approach from the street to the south garage bay, that will be an awkward s-bend turn that may take a few tries. Look at moving the driveway entrance down further to the south for a more straight on approach.
Small things since you have the chance to do it right the first time: solid doors instead of hollow core, antimicrobial paint in the bathrooms, double stud walls with insulation between units (sound is the new asbestos in multi-family), 5/8" drywall throughout (and something special/strong in the garage - see above), if ceiling light/fan combos - get the switch with the controls in it so the tenant is pulling on the fixtures chains and no remote to loose.