This is the first Boss product I've actually been impressed with since I was 15 years old with a no-mids Metal Zone into a Fender.
The tuner is very responsive (tracks well) and the readout is smooth, the controls are logical and straightforward, and it features a parallel output and 500mA 9V DC pass-through to daisy chain more pedals. It even has a tuner on/off switch input (in case you want to remotely switch), which could actually work because the thing is freakin' ginormous for those with vintage eyes. Like Mike.
Plus... my co-guitarist just snagged one for like $70. There's one on Amazon for $110. Compared to the basic staple TU-2 tuner, it's a much better buy if you're gigging.
Plus is has cool blue lighting!
It's the size of my bass pedalboard