I just played these 3 heads with a p-bass thru a markbass 2x10 cab. The MB-200 was incredibly loud and Nice sounding. It had a great tone with the bass and treble slightly around 10. I felt like it could cut through a dense mix very easily. It had a great clean rock tone. The PF-350, sounded like an ampeg but slightly more polite then what i usually like from an ampeg not as much grit. I liked it but i had to play with the EQ to get to growly rock tone that i like Tonewise my favorite one was the micro-vr. Just the tone i have in my head, just a nice growly p-bass rock tone. It sounded great with everything flat and awesome with the mids on 10. While i tried them, the salesman t'ils me that the Mb-200 was compressing a lot at high volume and sounded better at low to mid volume. He also told me that the PF-350 was losing its punch at high volume, and had his best tone at mid volume. He told me that these little bass head sounded great at a specific volume! If you own one of these heads, do you agree with the salesman's comment?