I'm on the Praetor. I doubt that the Phenom/Challenger are very different, but ILC is probably completely different.
I like working at Flexjet, and I think they treat us well. But the overnights are definitely a very weak area compared to a major.
The hotel will almost always be a pilot prison near the airport. Sometimes, when they have no choice, you luck into staying in what passes for small-town downtown. I'd guess that happens to me maybe 5 times a year. Once in a blue moon you might stay in a nice resort in someplace like Cabo because you have an early live leg the next day and the less-nice resorts are full.
Unfortunately, even with a long overnight they'll keep us on hotel reserve for the full 12 hours in case something pops up. You might be "finished" in TEB at 14:00 and think "great, I can go into the city!" -- but you still theoretically need to be wheels-up 90 minutes from a phone call, and that might last until 21:00 depending on when you started your day. So although long overnights do happen, the circumstances in which you can actually (legally) do anything with them are pretty rare.
Even if I'm babysitting a broken airplane, they _still_ have me on hotel 90 the whole day. Maybe another crew will call sick or fatigued; maybe the plane will magically get fixed early; maybe they'll airline you to another plane? They want to keep their options open, and that keeps you more-or-less tethered to the hotel area.
Very very occasionally the situation is so obvious that I can go do something in the confidence that I won't be called, despite still being on duty. I've been in Aspen on an afternoon where the winds would never allow a takeoff, so I went on a long hike. Or in the Caribbean with an early live leg the next morning, and no other Flexjets on the island, so the odds of the plan changing are low (but not zero!). This is nice, but rare.
On the other hand, at least FBO reserve is practically unheard of. You may still be on duty, but at least you're cut loose so long as you stay nearby.
In my experience, we go to some pretty neat places, and almost never get a chance to enjoy them. If I could change one thing about the job, it would probably be that.