Hi again, Piotr! I resteemed your post simply because I find it valuable and worth the read - there is no need to do anything for me (you know I charge one ethereum for resteeming, right? Just kidding :)
So far I am a steemit member mostly to follow other people and update myself with TA and fundamental about crypto..probably at some point I will be more active with my blog.
Concerning Ark, I think I more or less summarized the gist of the project - it is a platform similar to Lisk (in fact the wallets, for example look surprisingly similar). However, Ark supporters claim that the delegating system with Lisk is flawed, whilst the one of Ark is way fairer (I do not know whether this is true as I haven't researched Lisk enough). Basically you vote for a delegate and receive a passive income of Ark based on how many arks you've got.
The project is still in its infancy, but is quite ambitious. It is based in France and in my opinion it is one of the most crypto-friendly countries in the world, so this is a positive thing. There are also some rumours that Ark might cooperate with the French government as Ark is involved with France's legal framework for ICO's.
Ark has been working on V2 - an update which will increase security and speed (even now the transaction speed is just a few seconds). Then there is ArkVM - the platform where the applications will be built with just a few clicks - one does not need to know programming languages in order to launch his/her own app.
For free!
Then Ark will be convertible to major currencies such as the euro and the dollar. And when Ark creates the so called smart bridges, one will be able to purchase directly other crypto (for example Ethereum, or Neo) via the Ark smart bridge. Plus one will be able to use the Ethereum blockchain through the Ark platform! In this way Ark is the intermediate between the other platforms.
The team is also great in my opinion - it has been growing constantly and adding professional developers. There was a lack of marketing (which might be one of the reasons why the price didn't grow as much as many other coins) but Ark fixed this issue by hiring a very professional marketing manager. I personally suspect that Ark didn't pay for marketing because they still had no working product, but as this is changing now (the first ICO will launch on the Ark platform soon), they will do lots of marketing now - Ark will be among the main players in Consensus 2018 (just google it, in case you still haven't heard of it). I think that this will be the place where many businesses will hear about this quite promising project and things might change for the better for Ark.
To sum up, Ark might be a long-term investment, not a speculative coin and growth might be slower compared to other coins. However, the project grows steadily and the team and the community behind it are two great assets which in the long run might prove to be the right path. I personally believe that 2018 will be great for Ark with lots of exciting developments!
I hope that helps a bit - it is more or less the base of Ark. Have a good day!