-i have a 2 Shunagrens but i have found that the cube can be insane on quite loose tensions, a lot batter than the tightness at witch it is unpopable
at loose tensions poops are 1/25 ish, you realy do need to be used to one of those things to be able to keep it from poping
-the moyu/yj sulong is a good cube but whenever you loosen the tesions a fair way the cube becomes complete crap, and off, but on fairly tight tensions it is very hard to pop
on fairly tight tensions the cube pops 1/550 solves
-the shengshu piraminx has never poped on me and i have done at least 15000 solves on it