Me Three! I concur with the last two folks that posted. We were the tail end of the second group, and went to 138' using 28% O2 EAN. We had a 5' -6' shark come within one body length straight at us before turning its belly to us and zooming down into the not-well-illuminated depths. My wife got a good pic of that. And, the shark feed while we were at the safety stop was pretty cool too. We used 32% O2 EAN for our other two dives that day. A playful pod of dolphins accompanied us for over half an hour on the ride back. The lead DM gave a very thorough, clear, pre-dive briefing each time, and the multiple DM's did a good job watching over each group, but not getting in the way of experienced divers in our trip.
The whole day trip with Amigos was great, but we had some hassle getting our supposedly pre-arranged, no problems, Nitrox tanks from Protech's dock over to the Amigos del Mar boat, but we worked it out. Maybe Amigos is less Nitrox-ignorant now - none of the DM's etc. were Nitrox certified, didn't really know much about it, and a few chatted with us about it on the ride back. We didn't ask for any refund / discount from Amigos for not using their air, so I didn't really understand why there was an issue, other than two competitors with a common pair of customers that week.
The Amigos boat used for the Blue Hole trip is a large boat, and a lot of people like to dive the Blue Hole, so I guess some might call it a cattle boat, but we really appreciated its seaworthiness and stability on the ride out & back. You can hire a smaller boat to take the trip, but the ride out & back in a smaller boat wouldn't have given us a nicer overall day trip experience.
We used Protech for all our non-Blue Hole diving, and we were very pleased with the DM's and boat crews. If you have DIN first stages, Protech had the DIN or yoke convertible tank valves readily available for us to use, for either air or Nitrox. Protech also has multiple tank sizes fairly readily available for use.
There was no inkling of 'cattle boat' with Protech - their 'big boat' was 'in the shop' while we were there, so only small boats for us that trip. Night dive with Protech was great - just us 2, the DM, boat captain, and one other diver.
All week we had a great pace for photo ops, with both operators.