Two things about Lux REALLY bother me.
1. Lux can't pre-detonate her E like Gragas can for his Q or Ziggs can for his W. This lets tons of kills slip away because your target barely slipped out of the AOE before you could even give a detonation command. You're generally left waiting 0.1-0.2 seconds after Lucent Singularity reaches its destination before you can detonate it.
2. Lux only gets the first application of her shield at the end of its cast animation, not at the beginning. That 0.1-0.15 second delay has killed me more times than I'd like.
However, whenever I bring these up, people seem to raise their pitchforks and torches at me, and say that those delays are intentional. That can't be right, right? I mean, Lux has enough counters already, why should she be held further back by tech-based clunkiness? That just sucks ass, IMO.