Started a thread on Jiuzhaigou with the hopes to maintain all questions/posts/TR's to one thread. Recently spent 3 days in Jiuzhaigou and will try to post as much details as I can. The first post is general logistical info, the second a review of the hotel, and third post the review of the park. It's long, but I hope to get out as much valuable info as I can.

Links:
FT Link on Award Travel to Jiuzhaigou
Wiki Travel
Wiki Page
Official Park Page

Travel/Getting there:
Other than hiring your own transport which some do from Chengdu, the options are bus or flying.
1. Bus. Plenty of info on buses at the above mentioned links. Locals told me it takes around 8-10 hours, real time not sure.
2. Flights. I flew from CTU (flights also from SHA,CTU, and PEK) which has your most options. Due to my 1 week decision of going, I was stuck paying nearly full fares on CA & HU, but it appears this airport has little discounts if best 30% of full fare. Recommend going to the airport early to get window seats, and try to sit on the left side of the plane if coming from CTU. This was definitely one of the most beautiful approaches I've ever had, rivaling landings at ANC and JAC. If you do it right, you can book award from cities like PEK/PVG. If using DL miles, you can use CZ/MU but you'll have to connect as no direct flight PVG/SHA-CTU. Use EF to confirm availability, but CZ does have it and can be used.

Transportation to/from JZH and around Jiuzhaigou:
1. JZH. Links above talk about buses from the airport, but if you don't want to wait you can hire your own cab. Cabs are pretty much negotiable, as drivers will not want you to use the meters. There is actually a big sign outside the airport listing the fares which are a "guide" for pax and drivers alike. You can try to negotiate, but they were pretty firm. Here are a few details regarding what I saw:
- JZH-Jiuzhaigou 200 RMB. Night time is 260 RMB. "Night" starts at 2030 in "summer", 1830 in "winter" - no mention of when winter starts. I paid 200 RMB to go to the IC Hotel. Was 65km and took about 55 min.
2. Hotels & the park: at the IC, there was always a cab waiting around or you can have the hotel call a cab for you. You can also have the hotel book a car for you for more. At the park (esp in the PM), there is ALWAYS long queue's of cabs waiting to happily drive you where you want, so cabs are very easy to catch.

Tip: If you fly here, the best probably is to negotiate with a driver for the whole time you are here. I did this and it ended up being really nice. 200 RMB to/from the airport to the IC, and 50 RMB each way from IC to Jiuzhaigou. I was able to tell the driver the times I wanted and would call him 30 min before I wanted pickup and he was there. Also was great as I got to talk to the driver the whole weekend asking about the local culture, customs, facts about the park etc. He ended up taking me to go buy some of the local specialties to at some local store. I'm sure I could have negotiated better than 600 RMB for the whole weekend (to/from JZH and 2 day trips to the park), but it was fair and I'm sure the driver was happy (he didn't work other than drive me).

BTW, I did watch the meter a few times as the drive used it to show to other pax that he was driving me. From the IC-Jiuzhaigou OW was actually 64 RMB via meter, and to the airport was 164 RMB, so in the end I really paid about meter prices, but got the convenience of the same driver every time.

When to go:

Anytime is great actually, as EVERY season will be different and thus a new experience (the locals told me), but keep in mind summers are crowded (esp weekends) and the the peak fall colors will be VERY crowded (as will hotels) be expensive. Best time though is fall as the colors are VERY pretty. I went Nov 5-8 which was about 2 weeks past fall colors, but crowds were definitely less. My recommendation would be to try to go RIGHT after National Holiday or at the tail end of peak colors. I would say end of Oct is a good balance of colors and less crowds, though around Oct 20th would be the best time IMO.

Where to stay:
Plenty and plenty of hotel options if you want to use ctrip/travelzen. If you want international brands, you are limited to IGH (IC or Holiday Inn) or Sheraton. I wanted to burn IGH points so I used it at the IC (full review below). The IC (called TianTangJiuzhaigou Jiu Dian 天堂九寨沟酒店) is about 4km north of the HI (which is located in Jarpo town), both about 30min south of Jiuzhaigou. On Google Maps the IC is called "Jiazhai Paradise Jiafan Ancient city. The Sheraton is a lot closer and cheaper. Note, I was NOT able to book a reservation at the HI online and neither was PC when I called them, so something may be going on at the hotel like the IC running both. Either way, the hotel is still a HI (at least from the outside) but looked rather quiet.

Otherwise, tons of Chinese hotels closer to the park in the town of Zhangzazhen (漳扎镇)

Altitude Sickness:
JZH is high, it is at 3500m and you will likely feel it unless already acclimitzed. So go slow. They actually announce on the plane (ok, in Chinese) that the cabin is depressurized to high altitude so you will actually start feeling light-headed on the approach. The IC was located at about 2800m and the park from 2200m-3100m. Stay hydrated, and take it slow and you'll be fine.

Weather:
Since I was here in Nov, it has pretty large temp swings. But expect this any time in this area where the air is dry and the altitude is high. During the day it probably got near mid 60s F (18C) but at night below freezing for sure, maybe 25F (-4C). I was definitely needing a hat in glove when hiking in the AM (see park review).

Where to eat:
The JZH airport has a few shops, and one restaurant inside security. Otherwise, there are are local restaurants in every town and of course the IC/Sheraton have restaurants inside (with higher prices). At the entrance of the park there is a large food area with fast food (KFC knock off), snack stands, and a restaurant (was closed when I was there). Also, half-way up the park there is a restaurant (which was closed when I was there).