Cryo EL84 vs non / JJ vs EH

Not familiar with this tube. Using in Scott Mapleshade mod LK 48 for a few years in another system. EH have been in whole time. I know nothing on current production tube, I buy NOS for other system. I've never used cryo tubes but have with other things with good results. My EH lit up a bright red shut it down, need to order next week, I listen to it every day, any option appreciated.