I used Memphis Tours. They were very good - very responsive. The tours they arranged were also good - I liked the guides. All of the arrangements were fine. They went out of their way for me, and made on-the-fly adjustments when needed/requested without problems.
Memphis booked the cruise for me. The ship was the Iberotel Crown Empress. The accommodations were fine - it wasn't luxurious, but it was comfortable enough. The common areas were good - I didn't use the pool since it was so cold, but it was nice hanging out on the upper deck. The food was o.k.
The tour guides from the boat were good. I think the more important factor with regards to the tours are who the other guests are. They'll group together people who speak the same language, so I was in a group with all english speakers. There were other groups for Italians, Chinese, etc. There were about 12 people in my group. There was one large family (about 8 people) who were a bit of a pain - always late, wandering off, asking silly questions.
Every tour had one shopping stop - e.g. perfume shop, alabaster shop, etc. When I was on a private tour where it was just me, I could cut these short - which is fine - I get that the company mandates these stops and the guides have to go, and they didn't care if I didn't buy anything and left after 10 minutes. However, when I was with a bunch of people who wanted to shop, then I had to wait.
I did enjoy myself - I liked the guide we had on the ship - he was very knowledgeable and experienced.
I was talking with the guide and the captain of the boat, and they said all of the ships are mostly the same. They all go to the same places, do the same tours, very similar accommodations, similar food, etc. The only difference with the higher class boats is that the accommodations (e.g. furniture) is better, and the food is a bit better.
Iberotel Crown Empress
Cabin