I do not grow either one but am pleased to see that you mention autumn color. Not something many will even think about.

I have a Festiva maxima that has striking fall color. It's not one I would have most likely bought, but is a favorite since I took a division from my granddaddy's garden when we were readying the house for sale. I love the scent, the full flowers if we don't have a downpour, and the early fall color, so I am willing to use a peony ring to support it. Prior to planting this one in my garden, I hadn't seen it in the fall so I was pleasantly surprised by the color. None of my other peonies do this.

I have both but have struggled to get them to bloom, probably not choice planting spots, so don't have a comparison to share. Just wanted to say that there is a 2nd peony forum here online that is a bit more active than this one is right now, you might be able to get an answer there. http://garden.org/users/join/LizinElizabeth/ It's also free, just have to fill out the same sort of member profile to get a user name. Also, if you're on Facebook join the Planet Peony group, very active with members with tons of peonies and experience, I'd be shocked if you didn't get tons of pics and comments to help you out.

I only have Bartzella. It is definitely yellow, but not a harsh gold color. Very vigorous grower and has bloomed really well here. Lost all my pictures from last year, wish I could post one for you. It has gotten a lot at attention from visitors

I don't have Border Charm but I do grow Bartzella. I highly recommend this itoh peony for vigour, beauty, and consistency. I have it grown under a peach tree and yet it still puts out great performance year after year. Its foliage remains nice and green until Oct. Its flowers are huge and have great form and hold up well in the heat. The best part is they don't need support. The only drawback is that it makes a terrible cut flower. I got mine from Solaris Farms 5 years ago. They sell good stock of Bartzella.