I agree, iron balusters should have a pattern in them. As bp pointed out, the difficulty is that you've got some stairs with 2 and some with 3, so making a regular 4-baluster diamond shape is problematic.. However, they also compounded the randomness by cutting some balusters off at the top and some at the bottom. If they cut them all to length off the bottom, then a pattern would emerge, though not a diamond. Look at your first photo above. The doubles are all the same distance from the rail to the top knuckle. So a straight line connects them all the way down, and that line is parallel to the bannister. The singles, on the other hand, are not. Look at the lowest 4 singles. They are all different distances from the bannister. Try taking some blue painters tape and putting pieces on your existing balusters to represent where the knuckles should be. Try just changing them so they're all the same distance from the knuckle to the bannister and see if you like it. If you don't, then play around with another pattern until you get one that's pleasing to your eye. I would probably avoid using the blanks and just go with a running pattern like single/double/single/double. Here's what we did. On the stair and the balcony sections even though we used similar pieces, we used them in different patterns.

Thanks for your responses. We are purchasing the iron shoes as well so that they can cover the holes. If we end up using the 2 part epoxy this might be nicely hidden with the shoes. I can't imagine this not being a typical problem for most people who replace wood ballusters with iron ones! I can't seem to find any advice online regarding this issue!

McClark, yes the carpet is a solid tan (light tan). I love an oriental runner with exposed treads, especially coming down to a hardwood floor. Wish I knew how to post a picture, I'm going to do a search how to. Anyway, as you intuited, the stairs are very linear. No curves. Only one side of the stairs have exposed treads/risers. Due to the design of the staircase the "back" side of the stairs goes to the wall and the builder did not put exposed treads on that side, the carpet goes to the wall. IE, only one side of the tread is exposed So I wonder how an oriental runner would look in an asymmetrical arrangement like that. I will try to post a photo. We used to have a big dog, a German Shepherd, what a darling. Of course he scratched up the oak floors in two houses but I'd have him back in a minute! No replacement yet but nonetheless I am still a big dog lover and always will be. Marti, those really are pretty staircases, especially the curved silver one. They are clean and light and fairly contemporary. Mine is dark and fairly traditional, the dark being my main objection. I really have to post a photo. I will go look how to do that now. Thank you for finding and posting the photos.

The current trend(unfortunately!)seems to be what I have, which is the first picture. At the time I built, 8 years ago, I wasn't given any other choices, probably because the iron was a fairly new thing for balusters. While I do like the scrolled style in the second picture, I would prefer the iron not be twisted, but very simple such as the last picture. The scrolls do look French, and had I been given a choice, might have gone with that design since I also choose to go with a decorating style on the French side.