My tube experience has been a little bit more drastic than most around here as a lot will tell you that tubes don't make much of a difference. My test proved to be a little different. When I first got my 5150 is was dull, muddy as hell and has no gain. Come to find out all the tubes were GT 12AT7s. My Uncle had his Line 6 HD valve and HD147 over so I snagged one of the JJs that was in it and put it in V1. The tone difference was insane with just one tube. So I ordered a set from Eurotubes, 4 regular ECC83s and 1 balanced for the phase inverted. Obviously going from 12AT7 to ECC83S made a big difference and should considering they aren't the same tube whatsoever. But then a year later the other guitarist in my band got a 5150 that was completely filled with sovtek tubes, specifically, 12AX7LPS and 6L6WXT. The sound was something I will never forget, it was glassy, every attack had this tapping on a small tube glass sound, it was bright, it was also tight, but it had not mids and it wasn't very thick. He hated it and replaced them almost immediately with JJs becuase he liked the way mine sounded. He even replaced the power tubes with the JJ 6L6s as well.
Some time later I removed the cheap Chinese 12AX7 from my behringer preamp to replace it with the 12AT7 I had from my 5150. One day I decided to test out that Chinese in V1 to get more brightness out of the amp. It was more bright, but the mids were gone and the high end was so fucking raunchy I hit two big palm muted chords and a few open chords and turned my amp off the put the JJ back in. The thing was I expected the Chinese to sound better, but going back and forth the JJ was remarked better.
Then just recently my JJ V1 went out, I had to buy a tube at guitar center the day before a show, the only 12AX7 they had was a GT, wasn't happy but I needed a tube that day. Didn't have time to put it in until we were at the venue. My amp was indeed brighter, and after playing with it at home I noticed it too. It became almost too pointy to sharp and there wasn't that characteristic of the warm mids I knew my amp to have. Its subtle, and may not show up in a mix, but I could feel it massively.
I think outside comparing NOS and JJs most other tubes sound the same, the big difference from brand to brand is the feel. Different manufactures have more or less gain then some others, JJs have more gain than any other 12AX7 and have drasticlly larger miller capacitance making them way darker, but most other modern manufacturer have closer specs. The small differences are in feel. So without going to JJ's or NOS, expect more of a feel diiference. Tubes aren't going to make your shitty tone magically better. If you don't like your tone, it won't be the tubes fault, but tubes in some cases can make more drastic differences.
I would always recommend JJs for bright amps, especially the 5150, they are too bright, need more mids and smoother highs. Darker amps, you should use anything else. Tung Sol seems to be popular in the metal world in terms of feel if you don't like JJ's in your amp so that is a good place to start. If you wan't a slightly brighter feel, then try EH. The more old school guys like their GTs and most pf the EU guys seem to like the 9th Gen Chinese. I think from the clips you posted Deigo, JJs will be your fit, if not that, Tung Sol. But still do not expect HUGE changes in tone.
Preamp tubes are relatively cheap, experiment for yourself. You may find you are like me, liking tones that are not so popular around here. You may not like what everyone around here likes, you have to find out for yourself.
