Can't say anything about the butler, but I can tell you about the ports.
Belize- if you can, book an outside vendor for a cave tubing tour. The only problem you might have is if the ship is late such as ours was.
Costa Maya- Pay the $5 RT to get a taxi to Majahual. It is a great relaxing day. Grab a massage on the beach and try some fried Conch- also gotta try the pina coladas!
Grand cayman - we booked an outside vendor - Moby Dick Tours for the stingray tour. You stop at sting ray city for some playtime with the stingrays, then they take you snorkeling out on one of the reefs. It really is a pleasant day.
Cozumel- pray that the road construction is done before you go. They were doing so much road construction in downtown, that there were hundreds of people trying to go on these tiny little sidewalks! But we did a little shopping then went to Paradise beach. We went in the afternoon and was glad we did because a lot of the people left already. Plenty of chairs in the shade with hammocks.
We were on the Emerald Deck in a mini-suite. We we on the Grand last April the difference between the oceanview & mini-suite was $75.00 pp. And it was well worth it - it was nice to have the balcony. However, it was more then a 100.00 pp not to sure if I would take the suite the only added bonus is the balcony. It was just my husband & I and there was 1 day we had our breakfast out there & a couple of afternoons i sat out there for an hour or so just didn't want the noise & crowds which we at the pools.
There was no butler service - we did get a robe each for the week.