I mean, I would take Tannehill based on what he has been able to do recently, I think. Tannehill does seem to be getting better, but it's just been such a constant battle with consistency. And it's so many factors that contribute to it too. Just limiting it to the scope of pure stats, Tannehill's numbers are better than Kaepernick's this year, but Tannehill's numbers might not even be better than Tannehill's numbers last year (other than turnovers and completion percentage of course). He looks to be on track to maybe score 3+ TDs in the next 3 games to pass his career high of 24 TDs. He doesn't look to be on track to pass 3,913 yards he got last year, and he is averaging about the same amount of yards per play at 6.66.
Tannehill has had to pass it less than he did last year so that might be better stats based off of that. It's tough to tell. He doesn't have that take over a game ability that he can tap into consistently, and he certainly isn't getting any help from the right side of his front 5. Dude is getting abused back there on nearly every down. Same goes for Kaep. With the lovely addition of Martin to his o-line, Kaep looks completely out of sorts trying to figure out how the **** to do anything with a constant rush in his face. It's quite impossible for any QB to handle pressure on nearly every down. Colin is also not a TD hoarder like the better QBs in the league, and neither is Tannehill.
I guess I would stick with Tannehill for now. Something about Kaep makes me think that he expended his good luck and has hit his ceiling as a player. Tannehill seems to fluctuate between awesome and iffy, but his "floor", so to speak, seems to be lifting under him, which is a good thing. Tough to tell man.
He has inspired as much confidence in me as his o-line has to him...not much recently.