Found by only 8.9% of players in the recent FRAMEWORK game.  I did eventually get it, but was very surprised it was common.  It's certainly not common to me.

The answer is simple, Les - I'm not very good at it!  I gave it a try a couple of times when it first started and did poorly in comparison to the other games.  In any case, three puzzles a day are enough to keep me amused.  I might try it again at some time in the future.

I think Roddles makes a good point.  As an alternative (and I've suggested this before) perhaps the player stats could include the number of times players have reached each scoring milestone.  That way, those who strive for maximum word numbers can keep track of their performance, and those who don't can just ignore it.

And while we're considering scoring issues, I've never really liked the names of some of the scoring milestones.  For example, 'best' is only the third best level.  So it's not really 'best'.  Maven and Cham (presumably an abbreviation of champion) could perhaps be better described as Expert and Genius.

I agree they should all be common.  What about logoff? 

I thought it was a bit odd too.  Although we probably don't use the word niggard very much in everyday speech, if you know the word niggardly, surely you'd also know niggard.  Both should be common in my view.

Negatived was the seed word in yesterday's Challenge puzzle.  I did eventually get it, after initially dismissing it as a non-word.  I can't say I've ever seen or heard it before.  I'm not even sure how you'd use it in a sentence.  Negative isn't a verb, is it?  It was played by fewer than half the players in that game, so I'd question whether it's a common form of the word.  It's certainly not common to me.

I tried merch (short for merchandise) in the recent CHIMERICAL game, bit no luck.  It's a term that's become quite common in recent years and is listed in most contemporary dictionaries.  Worth adding to the Chi lexicon in my view.