If you Deadlift & Squat heavy on a regular basis, there isn't any need for SLDL's/Good Morning etc., imo. I do my Hammies on Quad day, and end up only performing 3 sets of 10 reps on seated leg curls(one leg at a time), after my Quad routine. Given that I have already done 5 sets of Squats, I count that as 8 total sets. Plus, on back day, I'm hitting another 5 heavy sets on Deads, which is also great hammy work. For that reason, I feel that anything more than the 3 sets of isolation work on leg curls, would be too much.