I have not tried it but here is a methylone megathread from EADD (where it is - or used to be - pretty common)
I appreciate it's pretty long but hopefully you can get more of an idea about it from there..
Here is a slightly shorter thread from Ecstacy Discussion.
From what I have heard it is only worth redosing once - after that you get all the negative effects (jitteriness, insomnia etc) with no extra benefits. Some people seem to rate it pretty highly..