Unfortunatley, I don't own one of these! A dorm mate down the hall does though, and while borrowing it that last couple weeks I've really fallen in love.
The overall build quality and design is excellent. For my uses, I'd say perfect. The kickback design is a great feature for jamming, really improves the acoustics. I've been using an old Peavey 1x12 100W, and I always find myself (and the drummer likes it better) placing it a couple feet off the ground for the right acoustics. No need with the Hartke, the kickback really sounds great!
The head unit is also spot on. Everything works well, as it should. The sound quality is excellent, really putting the old paper-woofer Peavey to shame. It reacts super-quick with its ported box, and hits hard. The overall tone and clarity is excellent, I've heard none better in this type. It provides plenty of controls on the face, enough for me. But if that isn't enough for you, there is a loop feature so you can patch in your own effect box.
Also, I've been using it as my subwoofer for my audio system. This may sound silly, but its really nice in the dorm room. Teamed up with 4, JBL Balboa speakers (Really love these) and your standard Sony 200W receiver. Placing the Hartke unit a few feet from my desk, I'm able to adjust levels for each album/track, or turn it off when its late... all while seated. I don't have these abilities with my current subwoofer OR the Peavey! All these inputs are really nice.
The only negatives I've found with this unit are minimal. The combination of the 12" alluminum woofer and a ported box made a 5-string bass lowest notes slightly distorted, the arrangment seemed taxed. I wouldn't recommend it for a 5 string bass, get yourself a 15" Hartke instead! Also, it's a practite amp people! It's plenty loud for small jam sessions, but I wouldn't gig with it. Cheers mate