1) The other posts gave the standard summary on the season, and advantages/ disadvantages. I was there at the end of August/ beginning of September of this year at the end of the dry season. Given that Salt Lick is right at the main waterhole of the park, animals visiting the lodge were very abundant. It is also not the most popular time, as holidays in Europe are just over, so it is easier to find reward tickets and the resorts are not crowded.

2) There are many options, here are a few:

(a) Go straight into Tanzania, the driver can drop you at the boarder close to the lodge. From there you can arrange a pick-up from one of the many tour companies in Arusha. (That is what I did.) I would highly recommend a visit to Ngorongoro Crater, Lake Manyara, and the Serengeti. (Splurge on the Baloon Safari also, even though it is very expensive. Mrs. Phxglobetrotter insisted that we do this, and as usual she was right! Truly the experience of a lifetime!)

(2) Masai Mara as suggested by other posts. If you go in August/ September, that is where all the migration takes place at the time. Later on, all the wildlife moves into the Serengeti.

(3) Zanzibar Island. (Went there after Tanzania.) Great place to relax for a few days after the Safari. Safaris are awesome, but also very tiring. You are in the car for a few hours every day, and typically up at 5 a.m. every day for game drives. Plan some time to relax afterwards, so you don't return exhausted from your vacation! (If you go there check out Chumbe Island! Small private islands with less than 15 guests at a time. Great Snorkeling on one of the best coral reefs in Africa. They have some 90% of corals found in that part of the world.)

(4) Seychelles. I have friends who went there instead for their resort experience, but will be more expansive than Zanzibar. I believe they now have a Hilton there?!?

(5) Mombasa. There are many nice and reasonable resorts there for a few days on the beach.

3) I found BA the easiest way to get a reward ticket. KLM via Amsterdam may also be an option. If you are going to upgrade, this is the time to do it! I was fortunate to fly in First on BA, but 20 hours on an airplane, a day layover in London, and the time make for an exhausting trip anyways. If you do fly in coach, make sure you have an extra day in Nairobi to adjust. Otherwise you won't be able to enjoy the Safari.

4) Yes! We booked with a very nice Safari company in Tanzania and stayed at the most famous lodges in the Serengeti. (Many won best hotel awards in various magazines.) The Hilton trip is very comparable, because you have a private driver the whole time, and the game viewing at Salt Lick is great. The Hilton lodge is a little older than the famous properties in Tanzania, so it is not as luxurious, but then you are there to see the animals. The service and food is as good as anywhere in the region, and the game viewing is top notch by any standard. (Paws Safari has the contract for Hilton, and they are a frequently recommended safari company.)

5) Availability should not be a problem! I even changed my dates without any issues!

6) I gave up my last day since I did not have the need to stay in Nairobi for another day. You need 5 hours tops in Nairobi! (Giraffe Center/ Karen Blixen House/ Downtown area, and dinner at Carnivore, that's pretty much it!) But if you want to use the last night after going somewhere else, you should not have a problem.

Please feel free to post any additional questions, glad to help!