This thread sorely needs some actual data. Personal anecdotes are of little value in determining the actual trends, because each of us is a biased observer of a small sample size. I looked around a bit on google and the most recent I could find is that Magic as a whole was doing very well in 2013, was up 2% in 2014, and I can't find much since then. Their 2015 numbers probably aren't out yet.
As far as this site is concerned, a peak in traffic in December may explain your relative experience of short term decline. I don't think it's indicative of any long term trend, per say.
So the big payoff for playing clues, as of right now, is tamiyo's journal. Getting to tutor up anything in your deck for 0 mana at instant speed is pretty broken. Currently I've been trying out blue and white, despite the fact that green has better investigators, because blue and white have fantastic draw-go options that create a sort of soft lock once you've got three clues and a tome. My current package is ojutai's command, archangle avacyn, and confirm suspicions.
So in the end, the deck has a consistent early game, with a lot of 3 and 4 of 2 drops and 3 drops, which are value creatures that give you more gas until you can draw a tamiyo's journal. At that point you've got access to a huge 1-of toolbox of answers and threats, some of which are at instant speed.
As far as this site is concerned, a peak in traffic in December may explain your relative experience of short term decline. I don't think it's indicative of any long term trend, per say.
I think I'm sold on thraben inspector, not as a 1-drop but as a follow up to erdwal illuminator or bygone bishop. jace, vryn's prodigy is another must-kill little creature, putting pressure on their spot removal. Reflector mage can help buy you some time while you're setting up.
So in the end, the deck has a consistent early game, with a lot of 3 and 4 of 2 drops and 3 drops, which are value creatures that give you more gas until you can draw a tamiyo's journal. At that point you've got access to a huge 1-of toolbox of answers and threats, some of which are at instant speed.