We were there in the early southern spring 2010.
The Hostal del Bosque offered excellent accomodations for a moderate price.
The service was very, very good. The administrators offered valuable advice on tours to different attractions, booked some of them for us without an extra charge and helped us to successfully locate a missing bag at Aerolíneas Argentinas.
Compared to similarly priced hotels, the Hostal has the advantage of a fine restaurant.
The only disadvantage is the location. Although within walking distance, a few blocks away form "downtown" and the waterfront, it is partly a steep upwards walk back to the hotel.
All in all, my wife and I had an excellent vacation in Ushuaia, we had good luck with the weather and we strongly recommend the Hostal del Bosque.

This hotel is located atop a very steep road, at least three blocks away from Ushuaia's main street (St Martin). It is clean, buy the mobilia is quite old and worn, so much that a door almost fell over me! Besides that, the wireless internet didn't work for me, and there was no water the night we arrived...

Stayed here for 1 night, got a really nice room with views of the mountain range, extremely toasty (it was very bitter outside) and nice décor. Location was quite central – 4 blocks away from San Martin St, but pretty steep climb up so may not be that suitable for people who have difficulties walking. For us it was perfect as being slightly off the main road meant lots of parking for us as we had rented a car.
Hotel staff didn't speak much English but communication between us and the staff was perfectly adequate using sign language.
Breakfast was good – nice selection of bread, croissants, fruit, yogurt, teas and coffee.

Hostal del Bosque is an awesome hotel! I went to Ushuaia with my parents, my 10 years old sister and two cousins in July 2010 and we all loved it!
For me, there is nothing to complain about this hotel. Actually, I have only good thing to say about it.
The staff was really great. All of them were so nice, helpful and polite.
The rooms were big and clean. The bed was not the best in the world, but it was good.
And the restaurant, oh, the restaurant! All the meals that we ordered were amazing. It doesn't matter if it was fish, pasta or meat, everything was delicious.
Well, I loved this trip to Ushuaia and I can say that Hostal del Bosque helped our trip to be so great. I loved staying there and, yes, I would totally recommend it.