First of all, I will admit that I do not watch many Russian movies. However, I heard about this one and sought it out. It was a good decision because it is a really well made and very interesting look at the side of the space race that is rarely covered in the West.
It's superbly shot, very well acted and the effects, where used, are top-notch. It is said to be a pretty accurate telling of the story and every bit as compelling as Apollo 13, as the crew had to overcome quite a few problems during their flight and when they got back down to Earth.
The leads all play their parts really well and there really isn't a lot of propaganda tub-thumping. It's just a great story about some very intrepid, brave cosmonauts.
It really is worth seeking out and watching!