The best about MU is it 1 GB file size, and as an uploader you know if you reup MU files you just sent the MD5 code then MU give you a new dl link

. Mean no actual upload.
The last time i'm using non MU premium is 2 months ago, i dl about 5GB+ per day and just got limit warning about once a month >_<. I don't know actually the MU limit.
Recently many user talk about file temporarily unavailable on MU. Look like it more frequently now. The last 2-3 months ago i can say it less than 1%. But now i need to check all links using link check before dl >_<. Sometimes i get 40% of the links are unavailable.
I like RS the most, it so fast, i got full speed all day. You need to wait 15 minute to dl next file. I also have premium on RS just use it to dl at night, dl while i sleep >_<.
I'm an uploader too, at least i use 2 mirrors MU and RS. sometime i use uploadjockey.. next month hope i can buy mediafire premium, so i can use the remote upload functions.
What ever happen i still upload to MU as a backup links. MU rarely delete copyright files.