No intrinsic sound quality, but you *can* do a lot with only 3 pedals. Less is more if it means avoiding over-complicating your signal chain. I use an old DD-2 delay, OD-3 overdrive/ or CS-3 compressor, and a TU-2 pedal tuner. There is room to put a old-style needle-tuner (eg TU-12) in here, but a dedicated slot would be handy. I find a pedal tuner more or less essential, but it cuts into your options when you only have 3 pedals. All powered with a Boss PSA-240, which fits into the case as well.
I put this box of tricks in front of a Fender Blues Deluxe when I'm travelling light, or when there's limited space onstage. The Boss is quarter the size of my regular pedalboard (not to mention the weight), and it fits into a laptop bag. Very handy.
Reliability/Durability:
Seems tough and durable, lightweight as well.
Ease of Use:
Dead simple, you lift the lid off, wedge your three Boss-sized pedals in, wire them up and go. There's a slight space issue if you use heavy-duty patch leads instead of the flimsy Boss ones provided. Better quality leads have bigger jacks, which bump up against each other here, and there's not enough room to jam the pedals right down.
A few extra millimetres would have done it, a surprising oversight by Boss.
Customer Support:
Never dealt with Boss, but my aforementioned DD-2 is still going strong after 20+ years, which gives some idea of their products' quality.
Overall Rating:
You are slightly limited to Boss pedals, but it's their product, so what the hell. Some other stompbox brands fit in here, you'll have to experiment.
Highly recommended, esp. if you can grab one on eBay.