i havent tried the restrictors, but was thinking about purchasing the round ones here before too long. i am using JLWs as my player 3 and 4 sticks (with square restrictors), and when switching between them and my u360s, the throw distance is dramatically different. i was thinking about getting round ones for all 4 sticks, but perhaps i wont now.
i also edited my 8way map, basically i increased the center dead zone by one small unit the entire way around, it made a huge difference in the performance for fighters