You definitely have a valid point there. I suppose it varies map to map depending on how the map presents itself and the opportunities available.

even in that case the combo is best used with ravage so you don't really need the extra range, which is why i feel the 20% impaling blades increase is also better. I mean the range can be useful, but, with a simple ravage>blades>grasp you pretty much land it all the time.

I read a lot of guide that say it simply isn't worth it because the combo does so much damage, but, I dunno if its different for me or what but, the combo doesn't do such insane damage that you don't need to do a couple auto attacks to finish the job. I think its a wonderful choice. It really helps kerrigan scale late game, and its not hard to end up with an extra 30+ damage if you roam and poke mobs with blades here and there. Don't get me wrong, primal grasp is extremely important but...