Rogue 88 Magnum upgrade

I'm considering the Magnum upgrade for the Rogue 88 amp(I have the Rogue 99 pre)and was wondering what others experience is with this upgrade. How does it improve the sound please ? Thanks
I just had my 88 amp upgraded a couple of weeks ago and am very glad that I did it. The amp now has total control over my Vandersteen 2CE speakers. There is now a very low and solid bass presence that wasn't there before. Music is now more detailed and sweeter. The new binding posts are also a big improvement.
Go for it.
I went from the sock Tempest to the Magnum Tempest . The Tempest is the integrated that uses the 88 amp. The improvement was very impressive. The extension in the highs and the bass from the 50% larger output tranformers is impressive as is the added authority from the doubled power supply. There are also some nice improvements in detail and resolution and complete freedom from any grain allowing the soundstage to really open up. It really transforms the amps into one of the best and uses the best parts available. The Electro Harmonix 6550's are great. Highly recommended. Have fun.
I just upgraded my 66pre to Magnum and am very happy. Better midrange transparency and smoother treble. And the blue LED is cool also... Mark O'Brien at Rogue is absolutely the best, he really cares.
Thanks very much for the feedback all. Sounds like it is worth doing. Happy Holidays. Len