Eating 'Golden Sun' Aralia cordata?

Udo, or its scientific name Aralia cordata, is a hardy, fast growing, woodland living, Japanese delicacy. Sounds perfect to me, except one thing. All over the internet its listed as hardy to zone 7, and I am in zone 5. But a little bit of research later I see 'Golden Sun' A. cordata, a common ornimental cultivar.

Now I am both intrigued and concerned, as a zone 5 pretty udo sounds pretty nice, but I am also aware that when it comes to ornamental cultivars of food species, they are often a) mislabeled species or hybrids and b) bred for how they look and not their texture, toxicity and flavor.

Has anyone here eaten 'Golden Sun' Aralia, and if so was it good? Does anyone know if 'Golden Sun' is even actually A. cordata? Has anyone grown it, and if so how is it to grow? And finally a long shot but if anyone has eaten udo and golden sun, do they compare?

Any input welcome

Missouri Botanical Garden has a nice write up on one called Sun King for zones 4 to 8.

 Young shoots of this plant are considered a culinary delicacy in Japan (taste resembling that of asparagus) where they are cultivated in underground tunnels. White fleshy roots (elongate cylindric rhizomes) are eaten as one would consume a parsnip. Udo leaves may be eaten as a vegetable when young.

http://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?taxonid=274056

I like to look up things I have never heard of and wanted to share that this one can be grown in Zone 5.

Hopefully someone who has eaten Udo will share their experience.

hopefully they taste as good as supposedly less hardy wild udo