When we purchased our home we had all the floors refinished and I thought I'd leave the stairs bare. That lasted a few months when I began to notice tiny little scratches on the oak. In 32 years we've only had 2 runners on the staircase. We replaced the first when we redecorated. It was about 20 years old and there was very little sign of wear or dirt. It was a good carpet - an Axminster wool with a small pattern. I don't like our current runner nearly as well since it's solid. As for Pledge on the stairs .....one year after returning from a long road trip DH thought he'd surprise me by having my Suburban detailed. It did look great but they applied Armour All to the running boards which not only made them shiny but slippery too. I didn't realize it until I stepped up and then promptly slid off. Glad you had the bannisters to grab - I banged my shin on the edge of the running board and had a nasty looking bruise for a week or two. I think you'll like having the carpeted stairs.

I think your installer is full of it trying to pass that off as "correct". Chicagoan's mock up clearly shows how it should look. No one would look at that and think 'the runner isn't centered on the lower stairs'. It's obvious the newel post intrudes into the space on those 2 stairs - your brain does not register that as the runner is off center. It's a re-do and I don't think this should be on your dime even if the runner has to be scrapped and re-purchased. If nothing else, your hand rail is on the right and most people will walk up the stairs closer to the rail so the placement of the runner now is dangerous.

Thank you to everyone for your input! I wanted to follow up just in case anybody else is struggling with the same decisions I was with a curved expanded bottom couple of steps in an old staircase. Despite some of the recommendations above, I did go with plaid and I absolutely adore it. So it can be done, but to get the lines to continue to flow in a consistent way took a ton of planning and hours of labor. But I love how it turned out. Thank you again for all the help And suggestions!

Thanks all, well, as is usually the case, consensus seems to be with the one that is my first choice as well! It is the more expensive one of course!! Thoughts on a border? I think it would look nice but wonder about stains on it potentially. The runner is wool which cleans up beautifully but a solid cotton binding may not.