The need to plant peonies in fall is grossly overstated :-) They are perfectly fine if planted in spring and I prefer to plant them then as I can confirm the name/color is what I want. I get mine at my local nursery, which typically has a huge selection right before Mother's Day.....after that, the pickings are slim. There is also a peony specialty nursery nearby if I want something very particular but they also have the biggest selection right at bloom time.

I just noticed that Spring Hill Nurseries is selling rootstock with 2-3 eyes, which is probably why one reviewer says it took a few years to bloom. I hope that's not standard in the industry! I do like watching perennials grow, even from the first non-blooming season, but I'd prefer my peonies ready to roll right out of the gate.

Look for potted plants in the spring - they will be fine. Only the bare-root plants seem to do best with fall planting. I've planted potted ones at various times of the year, and also bare-root ones in the spring and summer when they were divisions from other gardners.

I am not a particular fan of Spring Hill - I am not sure what you were looking at on Garden Watchdog, but in the last 6 months they have had 4 positives and 2 negatives; over their history they have almost as many negatives as positives, along with enough neutrals so that fewer than half their reviews were positive. To my mind, that's not a company I want to support.