Being as you already drafted Blackmon, I'd probably go Kuechly. It would help to know what the rest of your team looks like though. Which position do you need more help at?
I would go Floyd, both are good picks but when there is a tie in value, go offense since there is more defensive options as free agents. Also I think Floyd with be the best WR out of this draft.
I would also go Floyd, generally offense gets you more points overall. I too believe he will post better numbers than Blackmon anyways. Talent like his won't be available at 1.16, but I'd bet you can still get some good defensive players that late.
Go Kuechly, he is a fricking monster! I live in Boston and am a huge Boston College fan and have season tickets to the football games. I have seen him and grow and can not even express to you you his potential. His ability to read the offense and react to the play is astonishing, he can be on the left side of the field and manage to tackle the running back on the right side of the field for no yards or even a loss...he is a beast! This year, as a junior, he had 191 tackles...Obviously he wont produce those same numbers as a rookie. But the potetnial is there...