Thanks for putting up with my wedding band and stacking questions. Do you think that stacking these two hands shrinks or takes away from my center stone?
Honestly, all the options look really nice! I would just wear whatever suits your mood that particular day - I don't have enough room to stack because the base of my ering is wide, but I have three different bands and rotate them throughout the week, just to mix things up a bit. eta: to answer the original question, I like your ring with the 2 bands, I don't think it takes away from your diamond.
I like all the combinations especially because you have a space. As lknvrb4 pointed out if they were all flush then it would take away from the main diamond but because there is a small space you see each as separate and distinct. However my favorite combination is your ER with the straight band. It looks just perfect. Though I also really like the curved band with it. Wear them as the mood strikes. All really gorgeous and different looks.
Like the others, I think it looks best with the regular straight band but I don't think any of your bands, or the stack of two, diminishes the look or size of your centre diamond.