The Atma-Sphere MA-1 should be a good match for the Talon Hawk given the Hawk's minimum impedance of 6.5 ohms (8.0 nominal). That should present no problem for the MA-1 to drive extremely well, and the speed and transparency of the Atma-Sphere should be a great match as well.
Jtinn has pretty well described the the overall sonic characteristics of the Atma-Sphere versus VTL, imo. The Atma-Sphere has more speed, transparency and definition; the VTLs will sound warmer and with more body. To my ear, the Atma-Sphere is more neutral in tonal balance.
You should be aware that my bias is towards the Atma-Sphere MA-1 given my decision to run my system with Atma-Sphere MA-2s driving Eidolons. I keep hearing from folks who bought the new MA-1 "Silver Edition" (the current production model) that they are pretty incredible amplifiers.
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