Got around to hitting level 30 with my vanguard in ME2, and I'm finding that I'm still really not using Charge much. Maybe I'm just used to the ungodly nigh-invincible destructive capacity I had with that class in ME3 and I find using Charge in ME2 to be too much risk for the reward. I did however use it to get myself out of a total mess in one N7 mission - Zaeed and Samara had both been taken down and I was getting swarmed by Eclipse mercs. Managed to pick off most of them from cover, then used charge to stagger their engineer commander and just plain beat the crap out of him - shields, armor, health. On the other hand, usually I have a Geth Plasma Shotgun, a Locust, a Phalanx, and a Viper for my weapons loadout, which means going to point-blank range doesn't gain much in a firefight. Having Heavy Reave as a bonus power also favors fighting from longer range.