I haven't done any kendo, but I've been doing Iaido for a little over a year now, and Iwama-ryu aikido for a few months. I've noticed that, while some of the sword-work underlying principles are common to the two arts, for the most part I have to keep them completely separate in both my mind & body.
In Iaido, the cuts are large sweeping circles, intended to finish an opponent completely by using the circular motion to draw as much of the sharp edge of the blade across (& through) the target as possible. What I've seen so far from the bokken suburi in the aikido sessions is a completely different kind of cut - almost looks like more of a 'hit', where the arms drop down first and the tip of the bokken blade flicks down sharply just afterwards. (Perhaps not a great description, but the only one I can think of at the moment.) Also, posture is quite different (I get told off for leaning too far forward in iaido class and too far back in aikido class at the moment...).
My advice (if a relative beginner can give advice?) would be go ahead and do both kendo and aikiken, but keep yourself aware of the mechanical differences that will probably arise.