I'm fine with the damage they do early on. They don't (and shouldn't imo) scale to keep that same damage ratio throughout the game.
I'm fine with their current durability, because it's far less fun being forced into a long game because superior macro play doesn't guarantee any objectives (Also, wave clear champs become a problem and extend games for far too long, without any fun on either side.)
I'm not fine with their targetting, it's been slowly getting worse for a while now. The worst offenders appear to be DoTs. I've notice that if someone applies a DoT, then walks out of range, and an ally attacks under tower, the tower can sometimes get confused - It's trying to target the source of the DoT, but can never find it.