The MoYu RS4M is a reasonable budget 4x4x4 with a stupid name, it features many of the standard features of new 4x4x4s and is somewhat a QiYi MS with MoYu plastic, as it is somewhat scratchy but not in a bad way. Out of the box it is a bit too slow and locky but with a fair amount of break in it becomes faster and the lock-ups stop happening so much. I think some people will like this cube so would recommend it to people willing to try a range of cubes to find their preferences.
This is my only 4x4 but I did my research and people seemed to like this one. I'm pleased with it, the turning is smooth and its a good size and weight for me. Seller shipped very quickly and I will certainly return as a customer.
It is a really cube but it locks up sometimes