Re: STUN Reduction
Well, in my experience that could be 40/40 PD & ED so it's not as bad. There are some other considerations like NNDs, the effect of not being stunned and such, but you have to get to a certain number of dice before it's always better than just straight defenses.
That being said, I wouldn't go for the combined. I do allow damage reduction vs. certain SFX apply to regardless of PD/ED. (just to avoid edge cases).
Of course, STUN only is suspect in my book since in most cases if your base defenses are high enough, you rarely have to deal with reducing the body. (And i've been in games with a few 15/16 reduction things running about)