I have two Excelleron 90's with ys 110's on them for the money these planes fly straight with no coupling at all. The quests I have seen all have coupling issues. So for pattern use the excelleron is the clear choice. As far as 3D goes the quest is shorter so it might have quicker response , I acually think the quest is a nicer looking plane but for flying, the excelleron will beat it hands down in pattern. As far as nose heavy with the saito 120 my 110s requre that i put the battery pack as far forward as possible to keep it from being tail heavy. I don't think that you would be really over powered with the 120 on the excelleron 90.