#1
So recently, I sold my Carvin V3M after being sold on a preamp-power amp set up because you can model the tube sound now. (My guitarist uses an Axe-FX he sold me one it)
Basically, I don't want a tube power amp. I don't want the extra weight.
Also, I want to use it for guitar AND bass.

So my first question is, between these two:

http://www.guitarcenter.com/Crown-XLS1000-DriveCore-Series-Power-Amp-105803787-i1516454.gc

http://www.guitarcenter.com/QSC-GX3-Stereo-Power-Amplifier-104832845-i1388204.gc

I'm basically sold on the Crown, especially with the features after I talked to the guy on the floor at Guitar Center about the features and being able to run a minimum of 2 ohms, so I wouldn't have to worry with ohm calculations anymore.

My second question is, I know this will be PLENTY of power for guitar, but do you all think that it will be enough for bass in a live situation?
I was using a GK 1001RBII head, but now I'm swapping over to this (with the SVT amp patch), so would the XLS1000 have enough power ?
Let's take worse case scenario, 2 ohm loads, at 200 Watts per channel. Is that 200 watts going to each cab? (I run a 2x10 and a 1x15)

(Sorry, I've never ran a stand alone power amp for music gear before.)
Guitar gear used:
LTD EC-1000 Sunburst (jb/'59)
'94 Peavey Reactor EMG loaded
Eleven Rack
Crown XLS1000
Avatar Traditional 2x12
Carvin Neo 2x10 and 1x15
Spaun Drum Kit
#2
Either of those power amplifiers will probably work out for you, but remember that they are both at the low end of their respective lines. In other words, they are not representative of the amplifiers that made the Crown and QSC names. It is something to consider if you plan to do some serious gigging.

Personally, if you are in the United States, take a look at the power amplifiers made by Carvin. You already had a V3M, so I am assuming that you can get Carvin stuff. Their power amplifiers are first-rate, built in the United States and they are very well-made.

Anything with about 400 watts RMS or more would be fine for bass. Just make sure your cabinet(s) can handle it.

Good luck! You should end up with a very versatile rig!
"Maybe this world is another planet's hell?" - Aldous Huxley
#3
Another consideration is powered FRFR speaker systems. You get an amp and speaker cabs in one. IMO there's no point in getting a flat response amp and then running it into a guitar cab. The colouration of the cab will affect the modelled tone.
Moving on.....