Do I recommend purchasing ... Err ... Yes. I managed to get my copy as a giveaway, which is available very occasionally. If I see it given away, normally I post a notice in this forum. But, If I had spare money (and didn't already have a copy) then, yes, it's one of the programs that I would buy. Having said that I occasionally do some graphic design for fun, and It works with my graphic program too, so it may have more value to me than others.
Is it easy to learn? Depends on what you do with it.
If you want to manipulate existing filters, then yes, it's very easy to work, you're just changing parameters that someone else has programmed ... in the picture below ALL the colours can be changed, bonds varied etc. etc.
2018.02.13_17h00m24s_001.png 707.7KB
1 downloads
If you want to design a filter from scratch, then it can get quite (sometimes VERY VERY) complicated.
2018.02.13_17h13m06s_002.png 469.94KB
1 downloads
NOTE: There are NO shapes in this filter, everything is created with the node editor ...
I've only developed one filter, and it was a relatively simple one. Typically, I manipulate previously constructed filters.