We stayed at Surfside a couple weeks ago. We were booked into a standard room but got a free upgrade to a family suite (aaallllll the way at the far end of Tower 2...)
Short-version review is that it was nice, but *very* value... If this were our only option for future trips we'd stay there, but would vastly prefer to stay at Cabana Bay or Sapphire Falls.
The extra space of the suite was nice to have, but for just one couple in the room the three beds were definitely overkill. Even if we were traveling with a friend, I think I'd prefer to have the living room and bathroom layout of Cabana's suites over the extra bedroom of Surfside.
Bus service was adequate, and I fully expect the two Endless Summer resorts to share buses. (Side note, the moving of Uber/Lyft pickups at the garages makes a HUGE difference for hotel guests using the buses)
Service at Surfside was a bit hit-or-miss. When we arrived at midday there were only two people working the front desk, and one of them was involved with a complex issue a guest was having with their package reservation. When another person finally showed up, they had to go staff the luggage desk because people were waiting.
Housekeeping was a bit lackluster, too. Floors had only been given a cursory cleaning. Bare feet encountered crumbs under the table and edges of the counter, betraying that the housekeeper hadn't pulled out chairs to sweep or get under the open counter/table.
We'd gotten down to the last few tissues, indicated by them switching from white to colored. The housekeeper failed to change the box, so we quickly ran out. Next day the empty box was taken but not replaced, and the trash was emptied but a new bag not put in its place.
Oh, and the towels... Yeesh! Thin, sandpaperey, yuck. We've had better towels at EconoLodge or Motel 6...
Lastly the designated ride-share pickup area. If they want people to use it, they need to provide benches and cover from sun and rain. We followed the signs to it for our pickup to the airport (and the Uber app even directed us there), but our driver went to the main lobby anyway. He said that of the half dozen pickups he's made there, we were the first to actually go where we were supposed to.
Overall not horrible, but these Endless Summer hotels will likely be our last-choice option, probably even after Aventura.
(And before you ask, yes I did relay all of this in my post-visit survey from the hotel)
Edit to add: Totally forgot about the evening we came back late from Horror Nights to find the TVs weren't working, not was wifi. Trying to call the front desk showed the phones weren't working either. (Obviously all connected as one system) Used cell phone to call number listed on room phone, was told the systems were out in all of Tower 2 and that they were working on it. They were back up and running by morning.
-Rob