Upgrading Integrated Amplifier - Musical Fidelity?


Hey guys, I need some input as I have an old trusty onkyo 9555 integrated but want step up in sound quality. I am looking at the Musical Fidelity m2si but do not know much about the Musical Fidelity line or sound signature. I like a warmer sounding amp and not too clinical. Looking for some suggestions in the $400-$600 range. 
apstoltz
How much power?

NAD has a lovely set of mini integrated amps I really like in that price range. The 3020D is one of them, but I think they have 2-3 models.
Best,
E
I've had the Musical Fidelity Nu Vista M3, which was highly regarded back in the day.   I found it to be more bling with little musical substance.  In that price range, I agree with NAD, or finding a rebuilt vintage Marantz or Sansui.