To be honest, I do agree that Lux's kit is very strong and is borderline OP. I just don't think the ulti is the part that does it.

It is very well to talk about it being a skillshot - and it is - but people seem to discount that in a chaotic team fight, it is very hard to dodge it. It is also very hard to dodge it when it combos after other crowd control, including slows.

The thing is that the cc attached to her skillshots are very strong and while they don't do amazing amounts of damage, they can shut down melee characters very hard if used in a proper sequence. It also denies ranged characters the ability to kite and allows you to reposition much better. The fact that it's pretty much all decent AoE also helps it be very good.

It took me a month before I mastered aiming that laser correctly and still I miss a ton of times due to Arcane Shift, Katarina blinks and even enemies walking out of it in that 0.5 seconds. The point of Lux's ult is for you to make smart decisions when aiming (such as cornering enemies) and is very forgiving if you miss (30 seconds)

However the payoff is Lux has an extremely weak laning phase. Her E which is her AoE farm costs more mana than her ult and won't clear anything even with the help of her passive until lvl 2 or 3 and her bursts aren't that high either. The reason we play Lux is because of her laser.

My match history as SUPPORT Lux says she's a bit too strong personally.