sergeyuI also considered Sabaj Da2, but bought finally smsl idea. For it you can read at least some tests and reviews, forum discussions, but for sabaj there is nothing. Yes, sabaj looks tempting, but again you never know that is inside, and whether all components inside are genuine or fakes.
(Just for example: Chinese MP3 players Zishan Z1 and Z2 have excellent specs on the paper, but some components inside are 100% fakes. There are many special forums discussing in routine way what exactly has to be removed from inside and for what should be substituted, and where these original components to buy. This is China! man).