I enjoy some 'fun' but not full-blown. I'd much rather see a nude girl rolling around, feeling herself, enjoying the mud, etc. than a girl laying there playing with a dildo.
To me, the one is more about the mud and how it is a turn on, while the other is just plain old masturbation which happens to be taking place in mud.
So in my opinion, a mud video should be erotic and can include masturbation, but needs to be about the mud and the entire body, not just about one small part of the body. It makes a huge difference to me.
Now take it up a notch by having 2 girls playing with one another. Again, it's got to be about the mud with touching included, not just another porn video that happens to take place in the mud.
I'm a huge fan of both XXX and PG mudplay, but XXX when it's clear the person is in the mud because they want to be.
With PG, it can be fun because there's a mischief to getting muddy fully clothed that can seem innocent, yet it can still be incredibly erotic and naughty seeing someone get muddy fully clothed (like in business attire it or anything that almost seems like a walking contradiction). A certain store ran by someone who was (appropriately) ousted from the site recently was excellent with scenes like this. You can get away with harmless public mud play while simultaneously (intentionally) providing someone's porn.
With XXX, it's fun because, well, it's fun exhilarating seeing someone cover their entire naked body in goopy, thick mud. And when the toys come out, the action of dildo play is naughty enough on its own in private, but in a public area AND covered in mud where you could easily be spotted? I tend to enjoy scenes like this the most when the person featured in the video actually has the kink/fetish or when they're visibly having a blast. And when they're unscripted (unless it's like Jayce when she puts on a prim and proper act, only for her true mud-loving self to take over halfway into a scene. That's always a blast to witness. ).
Both PG and XXX mud scenes are incredibly erotic in their own way as long as (just personal preferences) it involves full coverage and the grade of mud is nice. I don't necessarily favor one over the other. Since I know XXX comes so naturally to you though, I'd say give in to all your urges...so for you in particular, I think I'd prefer hardcore on average.
Best of both worlds can be a scene that combines the two (first half PG, second half XXX).
Xxx for me should only be done if the person in the mud is fully into that and will be turned on by it otherwise it will just be a lot of fake orgasms and then it doesn't work in the video, and pg mudfun is always great but I prefer a model to show at least some skin in a mud video
As a general philosophy: bigger and more crazy/extreme is a good thing. I love anything that takes the common themes of WAM and pushes it 1 step further by doing things that you don't see very often. Mud is a fantastic medium that I feel could really be utilized in grander ways that it typically is. So... I say yes. I do prefer mud scenes that go all out.
I'd like Stella to comment since she's been able to pull off what I would be trying to type
One can lead to the other but few pull it off because they don't immerse themself with the mud they focus on being in the mud but not one with the mud.
I would prefer the xxx messy mud scene. It's so much better when the model is naked and enjoying the mud all over her body while she's masturbating and has a complete orgasm. Now if it's two models that are making love in the mud while they are nude that's even hotter. A the best example to this answer is none other the Mud Puddle Visuals hot scenes for this list: Skylar and the Mud Bubbles, Return of the Swampires, Summer has a Mud Bubble Face, Summer Messy in the Mud Bubbles, Messy Friends Nyssa and Summer, The Silver Bullet, Anabelle's Messy Mud Fun, Anabelle Gets Bigger Bubbles, Sarah's Mud Spa Arousal, Tied and Dunked Sarah and Annabelle, Little Butt, Big Bubbles, and Stairway to Heaven Nikko.
Love you, too
I tend to enjoy scenes like this the most when the person featured in the video actually has the kink/fetish or when they're visibly having a blast. And when they're unscripted (unless it's like Jayce when she puts on a prim and proper act, only for her true mud-loving self to take over halfway into a scene. That's always a blast to witness. 
). 
