one may say, it is not who is to say, but what is to say. get it? got it? Goooood. :)
CT-ART for Peshka

Yes all that has been said above.
I also have CT-ART 3 and recently upgraded to CT-ART 4 and have not regretted the decision at all.
The program is much more intuitive and cleaner than last version. I would suggest making the leap :)
GL
I have 4.0, and I also don't see any level such as 10, 20, 30...
ChessCafe review tells me that unlike 3.0, it doesn't have the ability to order the puzzles in difficulty. It can only do so within a certain theme.
Is it ture? If not, would someone please show me how to do that step by step?

I own it also. There are 2 subdivisions of the program "Themes" at the top and "Difficulty" on the bottom where the exercises are sorted by 10, 20, 30, 40, etc. level of difficulty. You should easily see it on that side menu where the exercises are listed. No need to setup anything (at least on the one I have).

are there any free download of ct art 4?
You should pay for it. Otherwise it is stealing.
well the peshka programs i had were really bad. i loved the old the ct art, it was much better, the board was bigger, it looked nicer and it showed several solution to some question. peshka doesnt show any alternative moves and is much to small. though i havent tried ct art 4, but its definetly that way in all other peshka progs i had. i tell you the old ct are and tactics encyclopedia and that stuff was way better

well the peshka programs i had were really bad. i loved the old the ct art, it was much better, the board was bigger, it looked nicer and it showed several solution to some question. peshka doesnt show any alternative moves and is much to small. though i havent tried ct art 4, but its definetly that way in all other peshka progs i had. i tell you the old ct are and tactics encyclopedia and that stuff was way better
I did not like Peshka at first either but I think they have greatly improved it. They do show some variations and it is even possible to play it out against the program sometimes.
Most of the courses seem really well designed now.
I own CT-ART 3 for Peshka.
When I start training I can choose max rating level of the exercises.
But I have read others using the CT-ART 4, that they can select level (10,20,..)
I remember I once had CT-ART 3 for winxp and not using the Peshka software, where I also could choose level 10,20,...etc.
Does anyone know if the CT-ART 4 for Peshka has the level 10,20,...
Or maybe there is some table that tells me what level 10 is in rating level?