You only need to look at the ship simulator forums (or read ship sim reviews – not previews) to see the general disappointment of Ship Sim fans; even avid shipsimmers are admitting that they are disappointed.
The screenshots you see on this page are from earlier development stages of SSE, the graphics quality had to be scaled down prior to release as they drained the frame rates (although the water waves are still quite nice, can't say the same for bow splashes).
Missions and free-roaming lack AI ships (well, you might see one or two if you're lucky – hopefully patches will fix this eventually). I have found that missions are also buggy and sometimes it is not obvious how to complete them (I'm sure these will be fixed through patches).
At this time, I don't think anyone can deny that fact that this game just ISN'T A FINISHED PRODUCT, and needed considerably more beta testing before being rushed onto the shelves to meet publisher deadlines.
VStep are working on patches at this time, but whether or not they will fix the game to a satisfactory level is uncertain (I am still unsatisfied with SS08, despite the patches released for that).
So if you are interested in this product, my advice would be to wait for, say, 6 months or so, and then check the ship simulator forums to see whether people are having nice things to say about it. Don't rely on the ship sim marketing and adverts, their job is to sell the product by convenietly hiding the games unfinished state and capitalising on the few good aspects. If you buy it now, chances are that you will have to wait for it to be patched to a playable standard anyway.
Until further patches fix (or rather ‘finsh’) this game, one star from me…