Cryogenic Tubes - Time for a Change

Well it finally happened, one of my (four) EL34 tubes in my Willsenton R8 blew up last night. I knew it was coming. The bias meter had been telling me for about three weeks that this particular tube was loosing its mojo. Before you ask, yes I kept adjusting it's bias to match the others, it just wouldn't stay there for long.

Based on curiosity I just purchased (4) EL34 cryogenic tubes. They should be here by Friday.

I'm curious what folks (with actual direct experience, not your usual "everything new is snake oil" folks) think of cryogenic tubes in their systems?

The benefits listed are: 

Expanded dynamic range

Smoother and more refined high frequencies

Increased Bass depth, definition, and articulation

Deeper and more focused soundstage

Lower dynamic noise floor 

Reduced micro phonics

Smoother midrange 

Lower operating temperature and extended tube life 

Thanks for your feedback (pun intended) and Happy Listening .