Ola Adrian,
I'm in Australia and can confirm that Spectro is a very good quality oil....I own a performance / custom Harley shop here in Brisbane, simialr temps to Arizona / New Mexico etc. with more humidity... We've used Spectro oils for some time in the Hogs and it's a great product. Using a fairly heavy weight tho...it has a history of being a quality product.
Not using it in my Berg tho...I use Dello 400....but I do use it in my Harley's