Question about Mont St Michel

I would do 4pm on…..

drive to Mont St Michel, leave our luggage at the Hotel Gabriel and take the shuttle to Mont St Michel trying to beat the crowds by 10 am?

I think you're saying you have a hotel room (on? off?) the Mont that night. Is that right? I don't happen to know "Hotel Gabriel."

There is a slight, historical error in your premise. Mont St. Michel now contracts with a huge infrastructure company to run massive, computer-tolled parking lots, which have busses along the 1/2 mile "strip" of on-shore hotels and retail businesses. About 2/10 mile from the Mont, an electric shuttle bus service takes those who wish it the last bit of distance. A healthy young or middle aged person could easily walk from the farthest parking lot space to the Mont ticket booth in 20 minutes or so. (Well, maybe slower with luggage in hand. But see below.) Other spaces are only 10 minutes from the Mont.

While the exact FOOT route you might follow can vary with tides, it is not true that the Mont is completely cut off from the Medieval pilgrims who are arriving every minute or two, during high tide. Hotels have private arrangements for guest parking, which I suspect is included, so you should discuss that specifically with your hotel.

Since you are staying there, you'll have plenty of time to enjoy it after the day trippers have left. If you are hoping to walk on the mud flats (we couldn't have cared less), you'd have to check the tide table against the excursion bus-horde schedule!

Edilt: Should have said that we were only there from 11AM to 3PM or so, with a car. We were sleeping in Dinard at the time, 3 nights.

The Hotel Gabriel is down by Hotel Vert and Hotel Mercure and others; it seems to be about a mile from MSM. I think I read that there are shuttles from the hotel to MSM. How close the shuttle lets you off, I'm not sure. I'm just wondering if there is a full day's worth of sightseeing on MSM. The abbey, and just wandering around looking at what else is there. Maybe the abbey is pretty much it. Just looking for advice and opinions :)

We stayed at Mont St Michel in early December several years ago. Touring the abbey in the morning was great. Having the rooms to oneself for just a few minutes was well worth it. The abbey doesn’t require more than two hours with plenty of time to linger, while the walk around about the Mont is even less. During the month of May you may encounter a much larger crowd thus requiring more time.

The views during the daytime were very nice. At night we simply gazed into darkness except for the shuttle causeway and some distant lights.

I've never been to Mont-Saint-Michel, but from looking at Google Maps, I'd say the entire island is about 500' by 500'. That means the total area is about 1/100 of a square mile. All the streets/paths seem to be on the southeast half of the island, so it doesn't appear you'd need much time to see everything outside the abbey.

I can't comment on the abbey itself.

I've noticed that virtually no one ever has anything very positive to say about the food on MSM. "Expensive and mediocre" seems to describe it, so I wouldn't be looking forward to having multiple meals on the island.

We have stayed on Mont St Michel several times so we obviously love it.
I agree that you will enjoy it more before/after the crowds have left. Therefore, I'd say to aim for the after 4:00 pm arrival. Rushing to get there in the morning will give you a very short window before the crowds start to get heavy. Of course, you could go early, leave when it starts feeling clogged, then return at 4:00.
I also agree that the food is, in general, expensive and mediocre.
What does it mean to you to "see" someplace? Some people think that you can see everything worth seeing and do everything worth doing on Mont St Michel in a short time. That may suit your style. Nothing wrong with that. But in my opinion, if you want to "soak up the atmosphere", you'll need a bit of time. You'll need to slow down and not just check the boxes. It's possible to purposely get lost on the island, knowing that, because it's small, you will soon re-discover where you are. The town is small, but it has many stairways and passages, which are fun to explore. Fun for us anyway. Only you know whether that sounds like fun for you.
There's a night time show at the Abbey, which can range from mildly interesting to very good. https://www.le-mont-saint-michel.com/en/discover/the-abbey/ Can't say what it will be like this year, but we'll be doing it again.
I can't imagine that you won't enjoy Mont St Michel, no matter how you approach it.

I would aim for 4pm. You will still have plenty of time to visit the abbey and walk round. There wouldn’t be enough to occupy me for a whole day there. It lost much of its magic when they built the road across the tidal causeway right up to the Mont. There are so many visitors during the day that it’s best avoided in the middle of the day. I was there in mid May, so not peak tourist season and it was full of primary school groups until mid afternoon.

Many of the shops are the buy-a-plastic-snowdome type of tourist tat and the cafes and restaurants were the worst we experienced throughout a 6 week trip to France - they don’t try hard as they know most people won’t be back. I have been back to this area subsequently and had a much better meal in nearby Pontorson.

I would do 4:00 on…We were just there April 20, arriving late afternoon and staying onight on the Mont. your hotel is partway btw the large parking lots and the causeway and you will have to flag down the often full shuttle to get on. It will drop you at far end of causeway and you walk the rest of the way. Plenty of people looked to be walking the entire distance. Be prepared for MANY steps. Once at the abbey I heard one person say it was 272 steps to go up. We were fortunate to be able to see low and high tides by staying overnight. It was very helpful and informative to have a guide for the abbey.

Thank you so much for everyone's input. I think we may just try to show up around 4pm and enjoy a "less crowded" experience at the abbey. A few last questions. Are there other structures on the island worth seeing, other than the abbey? Is there just a road up to the top? Is there anything to see on the edges of the island (other churches or buildings) and can you get to them?

There's a main street, La Grand Rue, which is what you will be on when you arrive at the island. It is cobblestoned and inclined unrelentingly upward to the Abbey. It is lined with shops, restaurants and hotels. A lot of the shops have tacky merchandise. Some have more expensive wares. All are tourist-oriented.
About halfway up, there's an interesting little 15th century church, Eglise St-Pierre.
Parallel to the main drag, on the side toward the Bay, are the ramparts, which also lead up to the Abbey.
On the opposite ("town") side of the main street are other smaller passages, staircases and walkways. Virtually everything leads up (or down, depending on your direction of travel).
It's a famous site. You can learn a lot more by looking it up.

I highly recommend you get off that main drag, and off even the outer, Eastern ramparts (though they are cool in their own right) for at least a chunk of your time there. The magic of the island really begins then you get away from the crowds and the shops.