Please excuse me if this was already mentioned, but what amp did you previously play? I got a VH4 but didn't really play it all that much due to volume issues in my apartment, but I definitely noticed it sounded good. A few months later, I started getting more and more obsessed with guitar gear, especially during my winter break for the holidays when I went back home and just had three weeks of just pure guitar practice.
I ended up buying an EVH 5150 iii combo to keep at my parents house for when I visit for holidays, and loved it. The 5150 iii is actually a really nice amp, especially for the price. When I returned back to where I go to school, I played my VH4 and actually had a hard time enjoying the tone, I started having doubts (7th circle of hell for me...right, and started actually preferring my axe FX 2 tone.
However, I gave it time and really sat there, just dialing in frequencies, getting a feel for the amp, and then purchased an EWS subtle volume control attenuator (great attenuator by the way) to put in my effects loop, and cranked my MV to 11-12. Slowly but surely, the more I went back to my Axe FX, the more I just, felt that I preferred the VH4 more. Your MV is at 9:30, but crank it to 12, it makes a huge difference. Get a volume attenuator if needed.
I know have a high regard to my VH4 now that i'm adjusted to the pure tube amp sound compared to an Axe FX 2.
I thought my VH4 was too loose and I also had the palm muting issues, but that was because my technique had to be dead on. If you palm mute too hard, then you're going to mute the strings...makes sense. Also, try using a boost pedal like a TS808 to tighten things up and get a different flavor for the amp. You have a great and powerful amp as a foundation, and it's just a matter of getting used to.
Also, KT77's are highly recommended, What are your tubes biased at?
Finally, try G12-K100 speakers, I hear they're more tighter on the low end and less fizz on top, which you might be perceiving as loose.
