So I kept playing and I quite like it. It took me like three four days to get far enough, partly because of slower pace of game but mainly because of me trying to learn most of it fast at once, via reading manual and forum threads. After that period I have kept playing the training game so that I am able to try few more mechanics myself (like research, design of ships, special route orders, automatic domestic shipments, jumpgates...) in this sandbox setting. And I must say going through this training game really helps (even in the shorter form).
I got interested in two features of this game: resource distribution and diplomacy.
1)
Resources are not completely randomly distributed but rather appear in some zones. It seems the zone you start in can have just two three resource types in abundance and two three more in such low quantities it doesn't pay off to mine them there. So to get more types of ore in decent amounts you need to venture farther from your homeworld, to star system probably already claimed by other realms. Getting of other types of ore will then need either lot of diplomacy or firepower. If realms want to shine here they really can't play just around their domestic planets and need to contact other realms.
Note that having more types of ore in your refinery means you get more resources from the same overall input. And the difference can be really big: with refining of 6000 tones of one type of ore you get 6x 1000 nanobits while with refining of 1000 tones of 6 different types of ore gives you 6x 3500 nanobits, both during 6 turns.
2)
Diplomacy screen offers you to demand normal things like ores, workers or taxes but also resupplying and repairing of realm ships in return of various treaties together with turnly aid of some amount of credits. That part made me recall my times with Civilization IV. One of features that is not too often seen in other game is a chain of fealty: independent colonies ("indies") found through the space can be added as territories to player realm and players can have other players' realms as vasals or sovereigns. That in turn makes me think of Mount and Blade or Game of Thrones. These bonds than automatically generate few types of points that can be used instead of normal resources during ship building and so.
I have managed to get few indies as my territories during the training game and am looking forward to some PVP connections in "real" game. It seems it can be
really interesting times.