My wife and I spent a week in Phuket and we ended up doing two Simba Tours, after being thoroughly impressed by our first tour.
We did the Phi Phi island tour, and the James Bond island tour. Both were amazing and I would recommend doing them both because they were very different from each other. The Phi Phi islands tour had snorkeling and a lot of pristine beach and lagoon locations, while the Jamea Bond island tour had no snorkeling but sea kayaking instead, as well as cave exploration.
Both times the driver showed up at our hotel in Karon beach early, and was very pleasant to deal with. He takes you directly to their office in the Royal Phuket Marina, where a light morning snack is waiting for you (boiled eggs, coffee, crackers, fruit, etc.). There's then a briefing of the tour on a large map that is very comprehensive so that everyone understands the days schedule and can ask questions. Both times the briefing was done by one of the tour guides named Harry who speaks perfect English. The tour guides themselves were amazing, we had Woody on our first tour and Harry on our second tour and I can guarantee that these guys are top notch. They really do avoid all of the masses, for example we were the first ones on the James Bond island, which apparently is very very busy normally. The tour guides know when the popular spots get busy and using the smaller boat (we had approximately 16 people on our first tour and 15 on the second), they are able to get in and out before the masses. The crew on the boat such as the captain and boat boy were always very friendly, often taking candid pictures of us, which they offer to email to you afterwards at no cost. If I could give more than 5 stars, I would! Highly recommend.