Assuming that is still the name as havent heard much about lately, how is this place for a group of 30 somethings. Or would they be better off ala carting at the boon or horny toad?

Asking for some 30 somethings. Would they benefit from all inclusive?

While we all know that SXM isn't really an all-inclusive destination, for a younger group, it might make sense, especially if it's a good enough value to allow them to leave the resort and experience the other beaches and restaurants that the island offers. A lot depends on their budgets and willingness to explore.

Probably would make everything much easier and the group could come and go as they please instead of trying to organize what to do and where to go.

Personally I wouldn't stay there, apologies but the clients staying there seem to be budget minded and they look it

we dined at their specialty restaurant last year and the hotel guests seemed to be out of place with not good table manners and not dressed properly

If they are partiers, I wouldn't recommend Horny Toad. HT is a quiet, intimate property where noise isn't appreciated. If that's how the group is, fine. If not, go elsewhere.

What kind of a vacation are they looking for? If they aren't big drinkers, there's not much point to an AI on SXM. (IMHO) The Sonesta does have a nice pool, direct access to Maho beach and an easy walk to Mullet. So if they only have a few days, that might be a big plus for them. However with so many good restaurants in Maho now - let alone the rest of the island - it would seem a shame to limit your dining options to whatever the hotel is serving up for you. If they are looking for cruises and water sports, they might find something in Simpson Bay more convenient. If they are big drinkers on a limited budget without much time, the Sonesta might work well for them - outside of that, I think there are better options.

Lots of VRBO or airbnb offerings I would recommend over all inclusiive. I have run into young persons staying there, they hated it. Watered down drinks and meh food offerings. Maybe hotel at Morgans -- close to a lot of places to beach, eat, or drink near there.

if you are the type of traveler who enjoys being around many many many people, tons of children, little to no privacy whatsoever, mediocre rooms (make sure you request not to be put on the street side across the street from the casino or you will be kept all night with loud noise coming from that area)
then you might like Maho Sonesta? Husband and I stayed there for one night last year at the end of our week - we are not all inclusive people at all, but it was the best for what we needed. We will never stay in another all-inclusive ever again. But that’s us! I know some people love that kind of accommodation! if you’re never going to leave and you want to drink a lot and eat a lot then I guess you might like it? I don’t know. It seemed kind of tacky to us.