I've got one and used it for over a year now.
Plusses: Small, lightweight, solid-state make it travel-friendly.
Sound quality seems fine to me.
I've never had a firmware problem with the unit except when trying to use it for playback with early firmwares. Recording has been rock-solid for me.
The level meters are acceptably responsive, but the peaking red LEDs end up being what I watch more (and they're quite handy and visible).
It'll power and charge via USB, so you can use a laptop as an external battery if you're on the road and have a laptop with you anyway.
I actually like TRS connections--they make the unit much smaller, and the cables I have to carry can be more compact.
Minuses: Yes, the non-seamless split is a major drag--fixing it's been a feature request of mine in their support system from almost the beginning. Thanks to this, I can't just set it recording before the opening act and expect that it'll span through to the end of the show, even though my card's big enough. It also means that I'm only recording at 24/48 (24 mostly for additional headroom, but it's not clear that it buys you much on the MT) due to trying to work around the 2GB WAV file size limit.
The internal battery is more of a curiosity than anything useful. I always end up plugging into AC or using a battery box, and that's more gear and more fuss. And all external power is via a USB mini-connector, which doesn't lock, so it can pull right out.
Even though it'll take professional (balanced) cabling, mine doesn't even come close to handling pro-line-levels. I guess the silver lining here is that I always run with the unit's gain ALL the way down, so I avoid a lot of noise from the unit itself. Of course, the sound guys don't like cranking my feed SO far down, so occasionally I get clipping; need to get some -20db attenuating 1/4" cables.
I believe the 1/8" input is only mic-level.
The supplied mic is, as you'd no-doubt expect, useless for pretty much any music purposes.
Any more questions? I'm happy to help.