We chose the cruise purely on embarkation port, destination and price - we didn't consider one cruise line over another. We were looking forward to eating lots of fabulous food and waddling off the cruise weighing at least half a stone more - but I think we lost weight because the food was, frankly, very disappointing. We booked the cruise 18 months ahead of time to ensure we had "my time" dining and wished we hadn't bothered because on day 3 we gave up on the "posh" dining room and ate at the "free for all" buffet for the remaining 9 days of the cruise.
We also felt that the cruise line were trying to "nickel and dime" us at every opportunity. We did have a bit of a fight with customer services over the mini bar in our room. There was no price list for the contents of the room fridge and, since we had paid up front for all our drinks, we figured that the water and soda in the fridge was included in the drinks package. Then to our surprise, a week into the cruise, $60 had been added to our account for "mini bar" ! Had they been adding the charges from day 1 we'd have been aware and stopped drinking the water in the fridge (we could get bottled water for free from any bar on the boat since we'd already paid for our drinks up front). We figured that the "mini bar" staff likely deliberately omitted to leave a price list so that we'd be charged and they would then get their 18% gratuities. We felt conned.
The ship also looked rather "tired" in many places with rag-like curtains/blinds in the dining room and broken fixtures in some bars. The bar staff were fantastic, however, and they were a major redeeming factor for us, making our post-dinner evenings thoroughly enjoyable.
Our cabin was fine. It was kept very clean by our lovely room attendant and the beds were actually comfy (although a bit too soft for my son, who likes a very firm bed). It was worth the extra money to have a balcony as we spent a lot of time relaxing on it, in the sunshine, watching the ocean. Had we not had a balcony, we'd have had to use the public areas on the top deck and they were very crowded. Our cabin was very quiet and at night all we could hear was the ocean swishing by (we were lucky enough to have weather warm enough to keep our balcony doors wide open 24/7) - very relaxing. Also, the shower was very nice and hot with plenty of power.
We booked our own tour with Guide Guru on the internet and they were totally amazing and much, much cheaper than the cruise line. We were in a group of just 6 (4 brits and 2 yanks) and our tour guide was fantastic. She took us to all the important "must see" places for two entire days and we didn't have to queue for any of the attractions (she got us into the Hermitage 15 mins before it opened so we could get "people free" pics). We even took a hydrofoil ride on day 1 and a canal boat ride on day 2. We heard from other passengers who had taken the cruise line tour that they had spent hours standing in queues, didn't see half as much as we did, and paid much, much more. Don't take the cruise line tours.
We were pooped by this time as we had just spent two very full days in St Pete so we just got on the Hop on Hop off bus and enjoyed the ride, with interesting commentary. Very good. We did get off for the dock-side market where we had an excellent lunch and meandered the stalls buying (surprisingly cheap) t-shirts, etc. Not like Oslo, which was stupidly expensive.