ADB in Xenoblade is great, though my favorite rpg combat to date was probably FFX. I liked controlling all characters and being able to quickly switch them in and out to deal with certain situations. I find in Xenoblade I don't use some of the secondary characters as much as I would like because I like always having the tank and the healer in the lineup. I would love it if I could swap in a swordsman or buffer to quickly dispatch a specific foe. If it was a 4-character party it would be better because then you could use that fourth spot for some creativity.
I do like seemless battles and movement in the battle scene and other features brought in from MMOs starting with FFXII. I think a great solution, on Wii U at least, would be to take Xenoblade's system and add touchscreen controls for secondary party members. Simply tap the screen to execute a skill. They would move and auto-attack on their own, but you would tap the screen to heal or use a spell. Your main character controlled by dual analogue and buttons. I think X may use this - as well as multiplayer - which could be very exciting.
As far as FFXV goes, I'm sure it will be either PS4 exclusive or multiplat so touchscreen options seem unlikely. But I would prefer ADB over the garbage that was FFXIII. I did not enjoy that combat at all.