I have two Tremoverbs and have long debated with myself about the Mark V.
I really need to go to the local shop and take one of them with me and set up in a room with a Mark V, Road King II, and a Roadster.
I have made many adjustments to the tone by adding EQ, using my GMajor, in the FXLoop, and by adding a little gain and EQ to the front of the amps using the Radial Tonebone SwitchBone.
This has dramatically improved my tone, sustain, tracking, (less mud, more articulation) and harmonics.
So now I have to bring my whole rig to the local shop...geez, or maybe not, as I love these amps.
I big part of me does not want to surrender the stereo/parallel rig, but I can't afford to just add a Mark V or any amp for that matter.
So this means selling the Tremoverbs and using a mono rig, which if you have ever used stereo/parallel, is almost unthinkable.
I also loaded each one with different SED =C= power tubes (6L6 & EL34) and they are very unique from one another with regards to overall tone, and I know alot of very reputable contributors have said that there might not be that much of a difference and I totally respect them, but to my ears it is huge, and maybe that is because of I spock mind meld or something, I don't know, but for me there is huge tone difference between these two identical combos when using the different tubes.
Using them together with the different tubes just makes for an amazing wall of tone.
Another thing that has really helped me to realize the potential of these beasts is adding a Marshall 1960B 4x12.
The combos lack punch and authority with regards to tight articulation or tracking, as they are open back and the 4x12 cures this problem.
Lastly, turn it up. You must let the horses run and move the paper on those **** speakers.
I have never been a fan of loud playing volumes, but I did it, do it and love it now.
The difference in tone is as night is to day.
I am not saying to play at stadium volume where the size of the stage places your closest cabinet 50 to 75 feet from you, but do crank it up, as the tubes and speakers react to that and I can't stress enough how this affects your tone and playing ability.
Hell, it has made me a better guitarist both in technique and creativity.
Just my .02 cents.
Sorry I could not speak to the Mark V and although I love my amps I would really like to compare the amps I mentioned earlier.
Oh, and lastly...alot of posts claim that the rectifier series is great for rhythm and horrible for leads.
In my experience over the last six years with my Tremoverbs, I have always loved the lead and tone capabilities of these amps.
In fact, it was not until joining this forum a year ago, that I even knew they were considered dark and in some peoples opinions not worthy of lead tone use.
Different people post varying opinions and facts that intrigue us & motivate our actions, as we are hungry for information.
12 years ago, I went into a local shop and played every amp they had, which included all the favorites, Vox, Soldano, Orange, etc. all high end boutique stuff.
I plugged into the Tremoverb and inside of five minutes I was sold.
It was not until 6 years later I bought two used ones.
As is, live playing and recordings were amazing...to me.
But then I found this forum and used all the useful information to improve on what I thought was already perfect and I have never looked back.
Hell, I am still tweaking, maybe because my playing has changed and my ear has changed. I roll tubes, eq, etc. in an effort to improve my tone. Hell, I am now working on speakers...Celestion G12s, V30s, X patterns etc. for my 4x12 and am thinking of getting a second 4x12 and investigating buffers for my FXLoop, as my pedal board already has a buffer in the beginning of the chain and at the end, just as luck would have it.
BUT! Now that I have improved on the tone and removed the dark tonal tendencies of the amps, it is even better and I thank Chris Mckinley for that. Just search my posts and you will find the conversations.
I am really sorry for the rambling and hope that I was able to help.
I really should not be on a forum at 6:20 a.m. in the morning on a caffeine high...I ramble, sorry.