...the key is in the root stock used.
I tend to agree with this.
The first choice in root stocks is generally
size (dwarf, semi-dwarf, etc.), and then cold hardiness.
Also important in selection are disease resistance, soil type,
water requirements, anchoring, etc.
There are dozens and dozens of available root stocks. Picking the best choice for your circumstances can be a daunting task. Some nurseries only use one type, while others will offer a wide selection.
Without knowing all of your requirements, I couldn't even begin to offer suggestions. What I do recommend is talking to a
local orchard, or better yet, ask your County Extension Agent. He/she
should know what works best in your region - minimum winter temps, soil types, rainfall/irrigation, diseases, etc. He has had years of listening to commercial orchardists complaining and/or praising different root stocks. He should know best what works well under your set of circumstances. Better to find out NOW than to wait several years to know if you made a good choice.