My current house is "reversed" as well. It's 3-stories/five levels to maximize the ocean views. First level is the foyer/garage, half-flight up is the master facing the ocean, half up from that are two guest rooms facing the street, half up is a story-and-half great room facing the ocean (over the master bedroom footprint). Half-flight up from that is the kitchen, dining room and library, all with ocean and street views. Every morning, looking at the sunrise and dolphins in the waves I know it's worth it to carry groceries all the way up!

I don't think you're going to find anyone who's going to say, "Garage sticking out in front -- YES! Just what we want." Ah, a closet. Given that it has a window, I was trying to make it into a tiny office space. Knowing now that this is a closet, I'd say make the master bath a little more narrow -- eliminating some of that unnecessary floor space between the sinks and the shower -- and allow the closet to be a little larger. As you say, more storage is always good, and you'll never miss it in the bathroom. Still on the bathroom: I still vote for a linen closet; it gives more storage for a lower price than linen towers, and it'll keep your dirty clothes hamper hidden. It's not the width of the master hallway that'll be the problem -- it's the turn. We bought a king mattress recently, and even bringing it down a straight hallway and turning it into the bedroom was tricky. The movers had to open my daughter's bedroom door and maneuver it back and forth a bit to get in the door. And a mattress has some "give". If you have a double or triple dresser, it'll never get into the room. One possible fix -- now that I know you're in Florida -- is that you might ditch the large windows in the bedroom and instead go with glass doors. In addition to being in keeping with Florida houses, you'll be able to move furniture in through the back very easily. Thing about the utility room space is that it's not laid out in a user-friendly layout. All that space is in front of the washer/dryer -- you can't hang things in that space because you need it for walking. And the washer/dryer are too far from the folding area.

Warm in the attic is not the primary reason for keeping the ducts indoors, it is pressure differentials induced by leaky ducts. In supplies, leaks cause make-up air to be drawn into the house from air leaks in the envelope. In returns, leaks cause air to be drawn out of air leaks in the envelope. (Poor return vs. supply balancing can do similar.) How high is the ceiling in the hallway? If there is enough space, the classic right way to do this is probably to fur down the ceiling for ducts and put the AHU in the attic within a sealed box that is made contiguous with the indoor space. Done right, the difference in ceiling heights can be architecturally pleasing.

I'm far from being a pro, but I've learned a lot on this site. Question: Do you have a pantry for storing food and groceries? Can you show where those things will go? What about your kitchen appliances? You want to be sure you have landing areas on each side of the stove/cooktop, fridge door not hitting the wall, things like this. Overall I think your house looks great! Highly disagree with someone's comment about completely starting over or ditching your designer. A few tweaks could be nice. I agree with the suggestion of flipping the laundry with the bathroom. At a deeper glance, I think things could be tight in the great room common area, but it's hard to tell without measurements. What's the path of travel in the kitchen, 36" ? 42" ? I think 48" would feel more comfortable for operating appliances, and perhaps you already have that. Personally, I like 4.5-5' but it also depends on the layout and where the appliances are going. If you could share the kitchen appliance locations that would be great. A room has 4 walls but your kitchen only has 1 wall for "stuff" because the other 3 walls are left empty or being used to travel from one area to the next. For this reason, a 1-wall kitchen layout has to be meticulously envisioned (the placement of items) especially for a big family with lots of needs/appliances. The space between the dining table and the couch should be at least 6' , but 8'-9' would feel even better. Again, hard to know without measurements. If it's something like 5', you're gonna feel very squished, no matter how tall your ceilings are. If things need to widen up and you're running out of space, you could explore the possibility of eliminating the dining table and doing banquette seating at the kitchen island, allowing for a wider path of travel between the kitchen counter and kitchen island, and a wider path of travel between the banquette seating and the living room couch. Can look very intentional and give you an airy feeling. Not everybody's aesthetic or preference, of course.