I can't get sweeps down for the life of me. 3 string sweeps I can get by with. Any more than that and the muting get's to be too difficult.
And I'm talking about CLEAN sounding sweeps on high volume with distortion.
Acoustic:
Barr chords. Don't have the endurance to hold them down so long. Hand gets tired quickly it seems.
Bass/melody fingering is tricky to get down too like haghj500 mentioned.