I enjoyed doing this puzzle. I enjoy doing every puzzle I tackle, which is why I tackle them. However I get more satisfaction from a puzzle I have to struggle over, feel like giving up over, over come that, feel it again, throw it at the wall, contemplate it in the bathroom (on the loo), in the bed, at work when I should really be looking at cervix, have to write to myself asking for a hint (since we all know inspiration comes immediately after sending said request), throw it at wall again (surprised that it sticks like spaghetti, inquire of children why wall is sticky), surmount the impassable obstacle of not being smart enough, send it in having mis-transcribed a c as an l or similar. So whilst I enjoyed this puzzle as much as any other I got less satisfaction from it, other than managing my first letter listener without a dictionary. Equally I enjoyed the maths one coded by the np and s, found it elegant (and probably easier than this one!), but did not get much satisfaction from it. I enjoyed the pi one recently, but recognised the digit sequence early on and so found it straightforward and not that satisfying.
Basically I see nothing wrong with this current puzzle. It was perfectly enjoyable, maybe not too difficult, but so what? I am sure I am not the only person to venture the opinion that it is nice to come across something that is easy once in a while!