I'm not a professional, so I use my ocarinas in my spare time.
This is my first double Bass ocarina. It sounds great, and It just took me just a few minutes to get in tune.
On the other hand, it's way bigger and heavier than a standard Alto, so I can't play it more than an hour or so.
Probably it will get better with time, when I'll be more used to the size and the weight.
The general perceived construction quality is good, and it's nice to touch the ocarina. Unfortunately my ocarina smells like tobacco (maybe due to the polish).
Anyway, I'd recommend this instrument to everyone who wants a good, reliable and easy to play double Bass.