Looking for an upgrate from Cronus Magnum

BTW I have heard and like the Cronus Magnum very much and have considered buying one from time to time, but only for use with the right speakers in teh right situation meaning the speakers are not bottlenecked by the limited drive power of the amp (compared to Pharoah).

Having right amp for speakers is fundamental to best possible sound, much like having a suitable performance engine in your car for optimal performance.

I run various speakers in my home (the better ones from largest, most demanding to least in terms of power needed to max them out):

1) OHM F5 series 3
2) Dynaudio Contour 1.3 mkII
3) OHM 100 series 3
4) OHM L
5) Triangle Titus XL

Cronus Magmum (tube amp) would be my choice for 5 maybe 3 or 4 in a smaller room if not listening very loud. I would not even consider it for 1) or 2) unless in a smaller room and no need to ever go very loud.

Pharoah (hybrid) for 1-2 and most likely 3 though it would do quite well with most anything out there so it is a safer bet if unsure.

The two amps will sound different in most any case though and its certainly possible that either might sound best to someone in any particular case. What sounds "best" is always a very subjective things whereas what performs best (and therefore has the best "chance" overall to also sound best accordingly) is a more objective thing.

As is pretty much always the case it all depends and you never know for sure until you try.

I wouldn't bother with tube rolling the Cronus Magnum.  I was in the same boat as you and I purchased over 300.00 worth of preamp and driver tubes.  I was happy for a week, then was unhappy again.  Although the Cronus Magnum has 100wpc, it doesn't seem to have the drive to power the speakers I was using.  I went back to solid state and couldn't be happier.  My listening taste is mostly rock, like Pink Floyd, etc and in that sense, the Cronus Magnum was a bit disappointing.

IMO it's harder to integrate a subwoofer into a system then to properly match an amp to speaker. Of the amps you mentioned the Krell Vanguard is a good starting point, it's claimed(have not demoed the Vanguard) to be a solid improvement over previous Chinese made models.

Quite honestly a subwoofer is the wrong direction if you want more bass definition.  You need to increase the power at nominally 100Hz +/- 20 Hz for bass impact and definition.  A subwoofer is poor at reproducing those frequencies.  
If your speakers have bi-wire terminals and your woofer to tweeter crossover is low enough (e.g. 2Khz max.)  you might consider adding another amp- e.g. parasound a23, and connect the Cronus sub outputs to the inputs and connect that amp to the woofer terminals.  
The CM has relatively low gain so you would need to adjust the gain on the bass amplifier by ear or measurements in order to match the tweeter level.  
Ideally you do this in a three-way system where the tube / low power amp drives the midrange and tweeter.  However there is no reason it couldn't work in your situation.
The tube amp will not even break a sweat while the solid state amp should deliver all the bass and drive you need.
I have done this successfully and am considering doing the same thing with my CMII.  

you guys with experience with the pharaoh- do you think it gives up anything in sound quality to the CM?  
does it have a sound signature?  
what type of speakers pair best with it?  
thanks.