Playing with other musicians for the first time, especially after noodling around solo for so long, has a lot in common with the process of culture shock. At first, there's a general wariness on the part of everyone involved, followed by a stretch of amusement and acclimation to musical quirks and customs, then acceptance, and finally (I often find) weariness and longing for familiar ground.
In other words, ad-hoc practice with a set of metal-heads didn't entirely end well. But it was illuminating.
Ultimately, experiencing other countries proves more of an education about your own, and that's certainly true musically. For example, my own context is rock- and blues-oriented, which means that I unconsciously base my playing and writing around the emphasis of certain beats in 4/4 time. I've gotten comfortable with that. But in a lot of harder metal and prog rock, primacy is given to the riff: a pattern of notes in a rhythm independent of the measure's basic beat, and which may even necessitate odd time signatures, like 5/4 or 9/8.
I don't know if this makes me a musical bigot, but I really hate odd time signatures. Four on the floor, baby.
But here's the other thing: when you come into contact with another musical culture, there are customs that end up being enforced. Just as intercultural communication, your role changes as you negotiate a common ground of understanding. And in my case, it ends up being constricted, which drives me crazy.
See, the job of the bass (or any instrument, really, but particularly bass) in rock music is circumscribed by the other band members. It exists in the space left over. If the guitarists insist on using distortion and heavy chords at all times, it cuts into the bass's ability to add effects or play in the upper register. Or, on the other hand, if the keyboard starts emphasizing left hand lines, now there's competition for the traditional bass role. You can try to fight for position, but I find that bass is at a disadvantage in these situations: it doesn't have the range of keys, or the volume of a cranked guitar rig (remember, higher frequencies require less energy to create at an equivalent loudness--and I hate volume wars anyway).
So the funny thing is, I got invited to jam because of my solo bass work, which crosses into a wide range of sonic territory, only to find myself relegated back to playing root notes on the clean preamp channel. Everything else got lost in the soup of distorted guitar crunch. I admit to being puzzled: this was not an unforeseeable outcome. So why invite me in the first place?