It is state of the art. The only tuner in small format that I know of that is a true strobe (it is actually more accurate than the Strobostomp... it has a virtual strobe display, but has true 'strobe' technology driving the tuning mechanics), almost immediate tracking (even of the open B... amazing), and true bypass (so it sucks not of the upper frequencies out of your sound).
The fast and accurate tracking of the low B was what sold me on the Turbo Tuner. I'd always resorted to tuning to a harmonic to get my tuner to respond in a reasonable amount of time. With the TT, the open B just works.