As a guitarist, I’m probably overly attached to tubes. I own over 30 tube guitar amps. I also own several solid state - digital and analog- guitar amps. They’re inferior - except for portability and consistency. Tonally, there’s no comparison. Tubes rule.
I also own McIntosh, Prima Luna, Manley and several SS Marantz - Ruby, Reference and a 2230 - hi fi stuff.
The Manley Stingray is EL84 based. In guitar world, EL84 is known to be easier to drive, suitable for low wattage amps and possess a desirable chime at lower volumes. The Manley fits the bill. It sounds great, gets to the sweet spot without cranking it up but the bass response is weak. EL84 based systems require efficient speakers. Still, a great sounding integrated from Manley. They build amazing stuff. But I would probably pass on an another EL84 amp.
6L6 is my favorite in both hi-fi and guitar sound. It’s clean, robust, powerful and has a ton of headroom before it gets flubby. Tubes are easy to find. The McIntosh integrated is 6L6 as is the Prima Luna separate. My main guitar amp, a Two Rock, uses 6L6. In guitar world, what are considered the best clean tones are almost always 6L6 based.
The Prima Luna integrated uses EL34, 6L6 or KT88. The KT88 is a fantastic sounding tube but I stopped using them due to reliability issues. They’re harder to find and their manufacture seems inconsistent. I’ve had several crash on me for no reason other than I installed them. But, when working, they were the most hi-fi, clean, round bass, beautiful mids of all the tube types.
EL 34, which is very popular in guitar, is probably my least favorite in hi-fi. They’re overly warm, with too much emphasis on the midrange. But other people swear by them. They’re able to handle a lot of wattage and they’re known for their reliability in demanding, high plate voltage environments.
My advice, if you’re young, is to buy whatever sounds best in your budge but try to get a system, like Prima Luna, that can handle different tube types. If you get bored, just roll tubes, it’s like getting a brand new system. Chasing tone through tube swaps is a life long endeavor. I have boxes and drawers full of old tubes. It’s a great hobby. Enjoy!!!