Went to see Cutting Edge at the British Museum late last year and it was quite an experience. Nothing flashy, just a bunch of old and pretty swords in display cabinets. You couldn’t touch them but, as silly as it sounds, they looked really sharp (and who in their right mind would go and touch a sword to see if it was sharp or not). A feeling you don’t get from holding a bokken (木剣), or an iaito (居合刀) for that matter. I think just seeing the proper katanas 刀 gave me new inside to aikido weapon training.
When you’re swinging a bokken you’re basically swinging a wooden bat, something that doesn’t cut but rather smashes. And that’s all right if that’s what you’re after— a bokken can be used like a hammer and probably works hideously well. That’s how Conan the Barbarian would swing it. However, if aikido bokken training is about studying sword techniques, then you really should try and cut with the instrument, not smash with it. That’s what seeing the old katanas reminded me of. When you’re a beginner, you should strive for speed, not strength. Sure, you need to have power behind the cut when the opponent has armour you want to cut through, but generally speaking it’s enough if the tip of the bokken moves fash and you’re relaxed when you cut. (Damn those shoulders, why can’t they just stay down.)
I suppose that’s it: don’t hit with a bokken, cut with it.