Brooks, I understand what you are looking for in low end control from an amp. In my opinion, any VSM owner in the market for an amp should hear the Joule OTL. It has been said many times, but it really is a special combination. And I think it will give you a reference standard for comparison with other amps when thinking through tradeoffs and benefits. You may forget all about a hybrid amp after hearing it. When I heard the OTLs at the CES in 2001 I knew I HAD to have it. I have the VZN80 and am very happy with it. Rich makes a good point about the amps but these things are all a matter of degree. It's like saying, "I like my Porsche 911 Turbo but I would rather have a Ferrari Enzo". The VZN80 was about as much I could afford at the time. If presented with the choice again I would probably opt for the VZN100. Not becuase they are that much different or better, but because you might as well for the little extra power and control. Size and heat-wise the 100s fit most rooms. When you start looking at the 160 or 220, not only does price become a major factor, but you are talking about some pretty large amps that generate a good deal of heat. I don't have the money or the room for them (my room is 14x24) but all else being equal - that'd be the way to go.
I have had my Merlins for 4 years now and they are not going anywhere. Many other owners feel the same, especially the guys with the Joule stuff. These amps will last you for the rest of your life. You might want to check with Jud or Bobby about when they will be pairing up again. Maybe they will in New York at the High End show in May? They're worth seeking out for a listen.