The only problem with PT's tab to transient feature is that the algorithm it uses to find the transient peak doesn't take ascending zero crossings into consideration. What I usually do is tab to transient (if I'm looking to start right at the peak), but then go back until I get to the nearest previous ascending zero crossing, and I cut from there to keep my edits clean and click-free. Or, if I want to keep the entire character of the sound including the attack before the peak, I just do it by eye and by ear right where the amplitude starts to increase up to the peak (again, with an ascending zero crossing edit).