Bryston 4B3 vs Mac MC462 vs Pass Labs X250.8, OR... GRYPHON Diablo 300?


Hi,
Over the next few weeks I am organizing in-home demo of  three pre/power amps for my B&W 803D2's, and will purchase whichever sounds best.  I will be testing the following gear, which is based on what's available where live:
-Bryston B173 / 4B3-McIntosh C47 / MC462
-Pass Labs X250.8, if I can get my hands on one (will probably use the C47 pre-amp to test with this)
The Gryphon Diablo 300 is also a candidate.  I've seen some strong comments from others that Gryphon is in another league compared to the others.
My question is, barring what sounds best to me during my auditioning, in general to most people would the Diablo 300 really beat the others in my list?  And, are there any material disadvantages to sound quality considering the Diablo is an integrated vs the other choices?  I don't really care about having separates, but sound is obviously important.
Secondly related to the Gryphon, there is only one Gryphon dealer that is even remotely close to me.  Should that dealer cut ties down the road, or go out of business, does anyone know how I might go about getting service for the Diablo should I require it at some point?  Is that a valid concern?  There are multiple Mac dealers near me so that would not be so much of a concern.

Thanks in advance for any feedback....


nyev
I am a sucker for being upsold, careful :)  Yes I could consider the phono module as well, but my goal is to, at some point in the future, to get a great turntable and as such I am thinking I'd be better served with an external phono module, possibly tube based.  I really don't know much about turntables or phono stages, but from what others have said, it seems external would be ideal.  Thoughts??  Also, should I go with the internal phono module in the future I'd be fine opening up the unit and installing myself.  In fact I'd enjoy that.  I asked and they said if you are comfortable working with electronics (I am), it is not an issue to install the modules myself.

By all accounts, not from my personal experience, current Gryphon's phono stage module is absolutely best compared to any other solid state integrated. At the very least, it is a very very good phono stage.
Sure, great separate tube or transistor phono will outdo it, I would guess for two or three times the cost plus interconnects and power cord.
And.. if you decide to add that phono module in ten years it may no longer be available.
So..?
All very good points.  I'll have to think on it!  I've had that exact issue happen to me in the past, where I had my upgrade path planned at the time of initial purchase and then when the time came I went to the shop and the key components were discontinued....  In that case it worked out as ebay saved the day and I bought used...
One other thing to add about my second audition of the Gryphon.  I actually enjoyed the 802 D3 speakers much more once I put my finger on what was initially making me a bit uncertain about them.  Yes the midrange is more aggressive than the D2, but it is also more revealing and presents very lifelike vocals as a result.  I found the Stereophile review of the 802 D3's and I think they hit the nail on the head for me - they said the speakers were great but noted that some may find the speakers too "light" due to the fact that the bass, while very deep and present, has no added "resonance" and no bloat and therefore can make the overall tonal presentation seem a bit light.  Once I realized this I appreciated the speakers more.  The bass is very deep and very present; it is just so well defined without bloat or "resonance" as Stereophile put it, that it makes the midrange appear to stand out more when listening to music that is lighter in lower level frequencies. 
Bass resonance must be present if recorded, just as body and resonance of other instruments in other frequencies. It should not be bloated unless, again, that's how it was recorded.
Yeah, as I like to think, the biggest audiophile mistake is not to spend enough, and second biggest one is to spend too much. You just have to define it in each case.
You mentioned possible great turntable in the future. Some will say that there are great $5k turntables while others will say that there is nothing great under $50k. Gryphon phono should be adequate for $5k table /arm plus up to $2k cartridge set up. But if you go higher, yes, no choice but have separate phono.