Thanks. All good suggestions here. The Mark V is really looking good to me right now. To be honest, I found more in common with the JP2C and the Mark V than different. I think they sound similar in many ways even though you can hear some distinct differences. The Mark V seems to be more versatile for single coil and humbucker pickups than the JP which isn't as good with single coil guitars in my opinion. I love the lead tone of the JP but there are a few great lead tones in the Mark V, so that's a hard one to decide. Some reviewers disparage the Mark IIC+ and Mark IV modes of the Mark V, but I used to have a Mark IV and it sounds pretty dang good to me. I don't miss my mark IV at all.
The Shiva 20th is a monster but my reservation is that I'm kind of an el34 guy. I played the 20th with el34 tubes and it did not have the same magic in my opinion. It's a remarkable amp though so it may be what I can always fall back on. On the Marshall side of things there is the JVM and the Dirty Shirley too. With the Dirty Shirley, it's only a minor adjustment in my playing to use my guitar volume to go from clean/dirty sounds. It's tone is so great that even though I am super impressed with the Smallbox, I cannot get my mind completely off of the Dirty Shirley. If it was a 2 channel amp then it would be so hard to pick one or the other.
The Satch JVM is not available for me to play, but I have listened intently to all of the videos and audio examples I can find and as far as I can discern, it is more capable than the JVM of better quintessential Marshall tones. In all honesty, I don't think the JVM should be abandoned though as I still find it very appealing in its own right so I cannot clearly justify the extra cost of the Satch JVM.
Lastly the Dual Rectifier since it's revision is amazing. It's like they took something off of the Roadster and put it into the reborn rectifiers so I like them very much now. There is amazing versatility in that amp so it's not like the Mark V necessarily blows it away in the versatility department. One thing about the Mark V is sometimes, not all the time, I wish it had more character like the JP. Sometimes it comes across as plain vanilla to me for whatever reason and I'll get bored of it for a few days and then it starts sounding amazing again. The rectifier never ever bores me so I think whatever it has that the Mark V doesn't makes it so attractive.
I thought getting some feedback on this would help my decision but I feel like I will regret not having another of them no matter which one I choose. Now I don't know what to do at all because time is short and I have to make a decision. My frustration level is mounting.
Lastly I want to consider things like build quality and support, but they all have good support. Even Marshall in the past has taken care of me. It seems like Bogner, Friedman, and Diezel have the superior quality, but there are a million Mesa Boogies and Marshalls that have toured the world without fail so it is unclear if there really is a such thing as superior quality past a certain level. What is the best option for starting a band? Should you buy an amp like the Smallbox that makes the best pedal platform or go with an amp that can deliver all the tones without pedals? Is there really a reliability factor at this level or are they all reliable?
By the way, I came across this awesome Dual Rectifier and I think it's so cool.
https://www.sweetwater.com/store/de...dual-rectifier-100-watt-tube-head-blacked-out