In need of amp upgrade suggestions

Interested in upgrading from our Simaudio Moon W-5/P-5 amp/pre power plant of 9 yrs.  Have always enjoyed the authority of the W-5, and would like to find something that really excels in low amplitude transient clarity, frequency balance, and can throw an exceptional soundstage.  Digital source is pretty hi-rez (Esoteric K-03), and cabling is on par as well (all JPS Aluminata).  Speakers are strong in efficiency (Daedalus Athena) at around 95db.  Recently auditioned a pr of Pass xa60.8's, but frankly thought the W-5 did a better presentation, less soundstage (I know, sounds crazy, but that's the way I hear it).  Open to push/pull, SET, or ss, but I suspect ss.  Any suggestions?   

Check out John Tucker's new integrated.

Don't let it's price deceive you. It's a giant killer.  

Paul Wakeen of Stillpoints just had one of these commissioned for his personal system.

If you're in the SF Bay Area, you're welcome to stop by and hear what his gear sounds like.  I have his current preamp feeding his reference 300b SET amps.
Since you have Daedalus speakers, surprised you haven’t looked at Modwright?  Lou is a big advocate of MW amps  driving his speakers, and MW gear is very well designed and supported. 
Though I have not auditioned in my system, I have listened to two different systems w/ Dan's KWA 100 and 150SE (one w/ Daedalus Ulysses, one w/ Magico's).  Just not the resolution I'm looking for - seemed a bit rolled off on upper frequencies and soft in midbass.  But just my impressions.  Both Dan and Lou are top-shelf individuals, and I trust their work and professional opinions implicitly.  I had considered two particular SET designs - Art Audio Adagios and the NAT se2se monos.  However, concerned w/ the former's current lack of support in the US, and sim. with NAT, just not much information, though what I have been able to gather via internet and colleagues has been descriptive of the sound I'm looking for.      

The NAT SETs have excellent word of mouth reputation for sound and rugged built quality and should work well with your speakers. I'd look at an 845 SET such as Line Magnetic 219 and the Coincident Turbo. Both have very reasonable pricing with very good reputations for sound quality.
Curious why you have no comment on my recommendation.

Are you unfamiliar with eXemplar Audio?
fliz - Thanks very much for your recommendation.  I'm not familiar with eXemplar Audio, but am now looking into and doing online research.  

50wpc seems like it'd be enough for 95db efficient speakers.

If you're in the the SF Bay Area, you're welcome to hear what his electronics sound like.

If you haven't already done so, I suggest you check out Lou's circle over on Audio Circle... this question has been raised several times. Not every one is using MW....altho I suspect it's near the top. 

It is great that you know what sound you are seeking, you have wonderful speakers, finding the right amp deserves equal care. GLWYS...
Mbump, based on what you’re looking for and your speakers, I would recommend either a Vitus SIA-025 class A integrated, or if you want separates and even more bottom end control, a Vitus RS-100 power amp & RL-101 pre. 

Vitus Audio is made in Denmark in thier state of the art factory. Build quality is excellent. VA gear sounds rich, detailed, open and musical. The SIA-025 is also on the warm side & sounds pure and mellifluous (tube-like). But it also packs a wallop. This amp uses a large efficient 1.4kVa shielded, potted ’floating’ UI-core transformer & would be delivering about 30 watts pure Class A and over 150 watts Class A/B into your 95db Ulysses speakers. Vitus measure power in "true RMS" which is a much tougher measurement, so don’t dismiss the power specs. I was driving a pair of Magico S5’s (88db, 4 ohms with a 2.4ohm dip) with an SIA-025 in a medium size room without an issue.

I would think either option would be a nice upgrade over your Simaudio gear & have good synergy with the rest of your system.
Might want to look at BorderPatrol ( I heard them at Capital AudioFest 2013 and felt they were incredibly good. Gary Dews offers both singled-ended and push/pull designs from his shop in the Washington, DC metro area.