Given the current market what specs would you consider poor, average, above average etc.?

Question is fairly vague.

I do not believe this market takes a quality dip like others.  From what I can see quality and tube specs have been constantly increasing (getting better) regardless of what this market is doing.

Yes, that's kinda what I'm getting at. I see everything from 21 SNR to like 40.

I've seen other threads on other sites giving a range/ranking, but they're like 5 years old.

I think you'll get better answers if you ask a more specific question.

Learn what each specification represents. Why you might want to focus on particular specs for your uses. Honestly, getting a tube that exceeds 18UM performance level spec is a good baseline. Anything above that is icing on the cake.

Check out this LINK

There are tons of resources here and on Youtube that explain each individual spec and why it might be important for you.

Start with the basics of mil spec being decent. Commercial tubes like the XLS are going to have those low SNR tubes you mention. I would just look for something 30+ SNR, 64+ resolution, with lower ebi/halo values and a clean screen.

EDIT: Double post

I guess a more specific question would be, where does 28ish SNR stack up?

I think first you must define whether you are talking thin filmed, unfilmed, green, or white phosphor.  After that, the specs become important.  In a head mounted goggle, I can’t tell the difference on resolution at 64+.  Higher resolution than 64 will inflate the FOM but not actual performance on head mounted units.  72 is fine.  Higher than that is for academics unless you are talking clip on I2 scopes.  You want S/N as high as possible, EBI < 1, and possibly Halo <1.    Of course with many suppliers you pay for higher specs.  With TNVC you can call your specs and get exactly what you want.  The higher you call it is possible the longer the wait.  The no questions asked return policy is there if you don’t like what you see.  That is what has made me a long term customer.

The last PVS14 tube upgrade to my first 2011 unit I called was unfilmed WP L3 tubes with S/N 38+, Res 64+, EBI < 0.7, Halo < 0.9 with no blems in zone 1 or 2 and small ones in zone 3.  I got exactly what I asked for and didn’t pay a dime extra.   All with a 10 year warranty and a company I know will be there 10+ years.

Mil-spec minimums for acceptance are actually way below 30 and mil-spec EBI's can be considered high.

Every XLS tube I have owned was 30 SNR or higher, granted yes there is usually a spec lottery if you are ordering new.

To the OP.. keep other vendors in mind.  TNVC has long wait times. Apollo has been putting out 36+ SNR L3 tubes consistently on a weekly basis.  Don't forget our friends at Nocturnality Gear either.

I've seen some of the Nocturnality tube pics, I prefer not to have big black spots in the tube. Maybe there is a reason TNVC has a long wait?

Check with them before you accept the “wait time” argument.  Also, I’ve seen “in stock” offerings at Koshur surplus that are good.  Benny also has pictures and specs on the actual tube available before you buy.    If you are an educated buyer, you can buy from anywhere and get a good product.  The rub always comes in the service before and after the sale, longevity, and ability to send back no questions asked during an inspection period.

Good luck brother!  Ping me if I can help in any way.

That's exactly it.

I had an XLS tube with a 21 SNR.

That's why I said start with mil spec. Omni VIII at 25 SNR isn't bad at all, and Omni VII was 28. EBIs can both cap out at 2.5 which while isn't great isn't horrible. Commercial spec units like L3 1701s can go up to 5.0 on EBI