I've dived with Silent World for three trips now, I think, so I'll give my 2 cents.
I got used to the lower level of service on my first Florida dives out of FLL, so I wasn't expecting a DM in the water or someone to switch over my tank. I don't think I've ever had a DM set up my gear anywhere unless I asked for help (which I did as a newbie). I guess if I had rental gear it might be set up for me. (Thailand was nice in that I could send my gear back to the shop with them and they would rinse if for me and bring it back the next day, but, hey, labor is cheap outside the first world.) But, I imagine if one asked for help at SW, you'd get all you wanted. I've asked for help changing out hoses and it was no problem, no grief.
The boats do hold 10, as I recall. I like that size, but never tried a six-pack in the Keys either. I usually travel solo, so a somewhat bigger group is a bit nicer in that regard.
Yes, the dive shop is a few miles from the dock. The morning of your first dives you stop by, pay, pick up your weights, Nitrox if you need it, and head to the boat. If you stay on Largo, the chances are really high that the shop is between your hotel and the dock, so I never found that much of an issue. Dropping the weights off after your last dive is more of a pain for me since I was usually heading back to Miami. But not a big deal.
Yeah, often you end up with two shallow dives. If that's not to your liking, ask for a different site at the shop. Days ahead of time if needed. If you don't get what you want, go to a different shop. Not every place dives the Spiegel every day.
The price can't be beat.
Finally, I will say that the new owners are not among the most friendly/chatty people running a dive operation that I've encountered. I don't know exactly why. One possibility is that they are British and used to a different level of friendliness in a business relationship. Another possibility is the pressures of running a low-margin business (with their rates) in a high competition market. The captains and the DMs are great, IMO, with Bob and A.J. leading the crowd.
So, that's my long-winded take on SW. In the future I'll use them if they are going where I want to go, but I no longer want to spend a weekend diving Molasses Reef, Grecian Rocks, and the Benwood. I've done enough of that to last a while.