Headamp: best build quality, parts cost to price ratio very good, wait times very long
EC: iffy build quality on some units, parts cost to price ratio very good, decent wait times. I kinda look at Craig a bit different from the rest of the amp makers...he seems to be more about building new designs and moving on to the next, not really in it solely for business.
Cavalli: build quality improving (newer stuff looks much nicer), wait times decent, parts cost to price ratio seems to be quite bad. I thought the LF and LL were overpriced based on what's inside...the LAu takes it to another level, almost a joke to me. People say that it costs more to build than it may seem, but that applies to all of these guys and I'm comparing ratios so I'm taking the other guys into account as well. Fact of the matter is that all of them are using custom parts, custom milling, engraving, etc.
All three seem to be really nice guys in person and I hope they all do well. None of them make any amps I'd consider bad...I've liked all the HeadAmp and EC amps I've ever heard, and Alex's stuff sounded 'ok' to 'good' to me.