Agreed, overkill wasn't the right word to use, but 40 watts certainly isn't necessary with the DI's......that doesn't mean having more wattage is a bad thing either. The ZOTL 10 would be plenty for the DI's, yet Terry London prefers using the MZ2 alone over the MZ2/ZOTL 40 combination and prefers the MZ2 with the Triode Lab 2A3 SET amp the most. Until living with one watt driving the DI's I would have never believed it would suffice let alone outperform the 220 watt SS monoblocks I was using before going to tubes. While the big amps were certainly louder, more dynamic and sounded very good, to my ears they didn't come close to the musicality and realism of the MZ2......especially with good NOS tubes.
Youre right Craig, Eric prefers large SS amps with his speakers. I believe he recommended Bryston to me. I don't dislike SS amps, I especially like the dynamic slam they can provide, but over the years I've gone from the likes of the ARC D400, Levinson 333 and Odyssey Kismet Monoblocks to small tube amps. Eventually I'll have an SS system for HT and rocking out to in addition to my DI/tube system.