They both have iffy ingredients, sadly.
Wellness has guar gum and carrageenan, as well as a few other fillers (potatoes and peas) that are potential allergens for some pets.
Holistic Select has cassia and xanthan gum, and flaxseed (another allergen).
Personally, I think Holistic Select is the lesser of the two evils. I avoid foods with carrageenan like the plague and would much rather feed cassia/xanthan gums over that stuff any day.
Proud parent of Scamper (age 12) and Robin (age 4)
At the rainbow bridge: Slippy, Faramir, Gabriel, Lucky, Ammy