Buying Seamaster 300m from Grey Market? Is this OK

OK, my first every post on a watch forum, so be nice to me please. Apologies in advance if this is a regular query.
I was passing through a Swiss airport last week and noticed a Omega Seamaster Diver 300 M 210.30.42.20.04.001. This is the Steel bracelet version with white face.
On the trip home I read some reviews and was surprised to find new, unworn examples at significant discounts from list on a well known watch reselling website.
I would have a slight preference to buy from a retailer, otherwise we will have no retail, but the price difference is not insignificant. I contacted the local AD and he acknowledges the grey market but says warranty will have been registered in advance. Is this accurate/ should I care. I am buying the watch to use, not as a collector...

Apologies again if in the wrong place/ a dim query. Not my area of expertise...🙁

But it is a nice watch.

OK, so my new Omega Seamaster Diver 300 M 210.30.42.20.04.001 is with DHL en-route from Monaco. Super service so far from Mall of the Watch.
Ordered yesterday, shipped today and due for Delivery tomorrow in Ireland.

Looking forward to opening the box😀

So, it arrived , less than 24 hours after departing Monaco. All appears in order, but just a quick check and back under the Christmas Tree (a long story) .

Looks great. Nice Christmas present!

So I presume Mall of the Watch is GM? The only thing you gave up for your discount is the factory warranty and in some cases, the original AD may have registered the warranty before selling it to the GM dealer (though it isn't likely). A GM dealer typically offers their own warranty.

The only other problem I know of is that some ADs will polish off the serial number so the manufacturer can't track it to them. I've bought most of my watches GM and the only problem I've had was a sticky pusher that the GM dealer happily fixed under their own warranty. Some GM dealers have spotty records on their warranty service.

Yep, they are GM, but saved a worthwhile amount (€800) Vs best offer from local AD. Watch has full omega warranty cards and supplying dealer is identified on the card. Obviously not to be named here, but I googled and it exists.
I explicitly confirmed with supplier that full international warranty applies. On-line comments appear to support this.
Cards dated Dec 2019.

Congrats, lovely watch. Like the OP, I prefer to buy retail from an AD when possible (support local business, etc.) but if the price difference is too big, then I go grey market. The cost of a service is my typical tipping point if the warranty is in question. Saving on sales tax is just a bonus.

Congrats on the beautiful watch! Getting a good deal from the grey market with full warranty is great. Enjoy opening it in a few days.

Congratulations, you got the best of both worlds.