I prefer my spas to be serene, so Banya 5 is less than perfect. You have your Russian families, but you also get what I call the Abercrombie set. They're young and their chattiness makes it hard to get fully immersed in what should be a peaceful experience.
However, Banya 5 is conveniently located and its parilka (dry sauna) is scorchingly hot (200 degrees F), so it gets plus points for that.
The facility is smaller than I thought it would be, but the hot tub is smaller still. So much so that it seems like an afterthought. Maybe the hot tub is not a key feature in traditional Russian baths? With four people in the hot tub, you are practically sitting shoulder-to-shoulder.
I do like the local touches. The tepid salt pool is kept at the same degree of salinity as Puget Sound. It accommodates many more people and is an interesting feature. The cold plunge (55 degrees F) is kept at the same temperature as Puget Sound and is deep enough that you can submerge most of your body quite easily just by slipping in. It's also small, but no one spends too much time in there.
The steam room is really nice. It uses just enough eucalyptus to get your nasal passages clear. It also gets steamier than any other steam room I've ever been in, which is a pretty cool effect.
However, my favorite is the dry sauna. It's like an oven, from the heavy Brothers-Grimm-style wood door to the stone fireplace that occupies a quarter of the room. The sauna is huge, though only one side has a bench wide enough to allow you to lay down comfortably. It gets hotter than any other dry sauna I've been in and really lets you feel like you're getting cooked.
The free teas and the nap room upstairs are nice touches. I also really enjoy the twenty minute, thirty dollar honey/oil/salt scrub.