Brendan and I visited this museum today (Tues-Sun 9am-5pm, closed Mondays, admission NT150) and were pleasantly surprised.
I've long been interested in Taiwan's aboriginal customs and cultures, although can't claim to have more than a cursory knowledge. I'm hoping as I spend more time in Taiwan that this will change. Not only do I think it's important for Taiwan to explore, celebrate and advertise its non-Han cultural roots, but it's also just plain fascinating to learn about cultures that existed before "Han Chinese" ever became an ethnicity...cultures that, from linguistic evidence, are theorized to be the root of all Austronesian cultures and languages.
It was well-designed and aesthetically pleasing, with lots of informative plaques and wall displays in English and Chinese. With a few exceptions ("Man's Knief") the English was pretty good. The flow of the place could be improved; the men's and women's hats in the basement should be on the 3rd floor with clothing and ornaments, but that's really a small thing.
It is not a large museum, nor is it tiny. At a strolling pace, you can take in the entire museum in about 2 hours. It's a very good way to spend a cold, rainy morning or afternoon and doesn't boggle the mind and exhaust the legs the way that the National Palace Museum does - I also think the inside is better-decorated and more streamlined than Gugong, but hey).
The basement houses spiritual items and other crafts, and has the biggest exhibition space; it's worth it to start any trip here in the basement after reading wall plaques about the various recognized tribes on the 1st floor. The 2nd and 3rd floors are quite small; one has pots and other daily life utensils, and one has clothing and ornaments. Only rarely is the information only in Chinese.
The biggest pleasure of this museum, besides learning a lot about the history, festivals and culture of Taiwan's aborigines is learning how greatly each tribe differs (I experienced this firsthand when we stayed with an Atayal couple after Pasta'ay and they knew almost as little about the Saisiyat festival as we did; they just went to socialize and see the dancing). The exhibits are made with an eye to the aesthetically pleasing, so it's also a pleasure to just wander and admire the artwork; the weaving, carving, pottery, metalwork and beading of various pieces. This is what we liked about the Sanyi museum; not too much technical information, just lots and lots of beautiful things to look at, soak in and admire.
Both the ticket clerk and shop clerk seem to speak good English. Don't worry about crowds; we went on a lovely Saturday - today - and the place was almost deserted. One group was being given a tour by the director, and a few random visitors slunk through. Otherwise we had the place mostly to ourselves. The big tour groups were all at Gugong gettin' their Han heritage on.
It's worth a spin through the shop; unlike many souvenir shops, it doesn't sell irrelevant crap. many of the items are made by aboriginal artisan groups and many make good souvenirs or gifts. I picked up a few printed greeting cards to send people for birthdays.
The park across the street with stone tablets commemorating the different tribes is a good place to enjoy a picnic lunch before or after your visit.
All in all, a very pleasant trip.
To get to the Shunyi Museum of Formosan Aborigines, go to Shilin MRT and take any one of the buses heading east (right) along the road in front of the square (Zhongzheng Rd.) to the National Palace Museum...not every bus goes there. Get off at the National Palace Museum stop and cross the street, heading in the same direction along the road you came on. It's just past the terrifying kindergarten that looks like a castle on the right.