It will hover for ever with the OS and the right prop, such as APC 12.25 x 3.75 or the 13 x 4
Mine is powered with a YS 63, OS F plug, Cool Power Pro Pattern 20-20 and APC 13x4W prop.
Hovers 1/2 throtle, unlimited vertical @ 3/4 throtle.
It is a Dream to Fly and the changes from the previous are worth the efford IMO.(I had the previous MADNESS also and flew it for aboub 1 year)
I bought mine from Mr Braeckman, excelent Service and Customer care!!!

Baper[8D]