I am thinking about upgrading my LA 100 MkIII to the 150. Jud says: more inner detail, extended top & bottom, better definition, greater dynamics, improved transient attack, and all this without any loss of charactaristic Joule tonal sweetness or purity. Very, very tempting for $750 upgrade. How could you lose?
My 100 is a nice piece...huge soundstage with distinct instrumental voices layered within it, timbrally accurate... large complex passages easily retain coherence. Very sweet, open, clear midrange. Very dynamic. Vocals are exceptional. Plus for a tube amp, it's *quiet*. No break up of LFs noted at all, not in large scale classical, not in rock nor R&B nor jazz. The opposite of hardness in loud passages. The usual knock on this pre is that, on the contrary, it makes music a little more beautiful than real life.
I don't play metal or rap or industrial and can't imagine anyone who does wanting this kind of sophisticated line stage. I found a good power cord to improve the Joule quite a bit, for dynamics & leading edge transients. A TG Audio SLVR did a magic trick with the Joule.
I'm not altogether clear on specs of 200, believe it had the Purist silver wire. Don't be afraid of either Joule. Just budget some extra for one of Bob Crump's cords.