Manley snapper vs Atma-sphere M60

Trying to figure out the best way to go between these 2 amps.  They'll be lighting up Tannoy Kensingtons.  I play mostly rock on CD's.

Any thoughts/comments......thanks.
Coincident Frankenstein 300B monos unless you like it really loud. Manley if you do and M60 in between

Push pull for rock. I use Manley Neo250, Neo300B SE/PP and Mahi on my Tannoy Kensington. 
Both are quality amplifiers made by reputable companies.  You really need to see if you can get an audition because it will come down to your personal preference.  Nice problem to have.....
You will never get better service than from Ralph Karsten at Atma-sphere, whether you purchase a used pair or buy them new. 
Thanks so far.  I'm really not sure the snappers will outperform the atmaspheres.....overall.
s1nn3r, I have not heard any of your equipment choices, but it is really beautiful looking gear in your listening room.
gwng8, I own Snappers and previously had a different model from AtmaSphere.  I agree that Ralph is one of the best for product support, but I found Manley to be very good as well when I had a problem -- friendly, competent service.

Regarding sonics, I had different speakers and it was years ago for the AtmaSpheres, so not relevant to compare.  Other than the different presentation from an OTL design, another consideration is the Snappers have a fixed output around 5 ohms while AtmaSphere amps typically perform best into loads higher than 8 ohms.  What is the rating for the Kensingtons?

Oh yes, EveAnna Manley often utilizes Tannoys for demos with her electronics and at one time (not sure about current) she matched the Snappers with Tannoys in her personal system.  And she loves R&R!
According to the tannoy manual nominal impedance is 8 ohms, minimum impedance is 5.5 ohms.
The choice of music isn't going to make any difference - the amps and speakers really don't care about that, and there really isn't any way to design an amplifier to play rock better than classical or vice versa.

Now bandwidth of the amplifiers might make a difference. The M-60s are full power down to 2 Hz. This is to prevent phase shift in the bass region, which can in turn cause a loss of bass impact. The Kensington is a benign load for either amp.
Thanks to Ralph for being a real gentleman here.  He replies to simply report relevant information without attempting a big sales push.

That is unlike a dealer commenting over at Speakers who continues to push the OP to come to their store.  If like Ralph, they could simply state what they see as positives in some of the products they sell.  But my sense is they continue to post, using the Forum as a sales tool.
For the Tannoys you may need only the Atma-Sphere S-30. And if you happen to see a used Music Reference RM-10 for sale first, consider it. 35w/ch, 25 if wired for Class A.
When in doubt, call Ralph at Atma-Sphere.
My MA-1's and MP-3 are the cat's meow...
Love the M60...had a chance to listen to them at local audiophile place and it sound so nice.He also said its was his favorite amp and coming from him who been in audio for 40 years and was a musician I agree with his opinion.
The Convergent Audio Technology amplifiers are truly the CAT's meow.
The Atma-Sphere M60, in my opinion, would be the ideal choice, 60 watts of purity, Speed, Dynamics, smoothness, Ultra low distortion and fatigue-free listening. It does carry the weight and emotion of the music you listening in a special way. 

If you do get the amp or any Atma-sphere amps. Make sure you get all the upgrades, Power Supply Boost, Caddoc Resistor Package and the Vcaps. Many Amps in my listening room worth even 4X the price have not done it all as good the Atma-Sphere Stuff. 

I agree...there a few amps I heard that sounded so nice.Like JaFox  mentioned the Cat JL series,Jadis JA series and the Atma Sphere M60.Cheapest in price is the M60 though and I could live with those for long time.
I'm running my Tannoy Canterbury's with M-60's and they sound incredible to my ears with all styles of music.
I've owned M-60 for 2-3 years and I love them.  They may well be the last amps I buy.  I've heard Snappers only once, and not in my system, but I don't think they are in the same league with M-60's.   One caution however, is that the M-60's don't lie.  They are not forgiving of bad recordings, and they are not forgiving of bad digital.  I don't play much rock.  Mostly classical.   I got in the mood for the Stones a couple of nights ago, and it was all I could do to get through Beggars Banquet.  BTW, I agree with @phantom_av on the upgrades.  Also, be prepared to do some experimenting on getting the 6SN7s right.  Makes a big difference in my opinion.   I would expect the M-60's to be very nice with the Kensingtons.  
He said snapper. 🤗
I love Rock music on the Atma-Sphere more than SET or Push and Pull. I don't know why but I always feel The Atma seem to handle complex music easily and feel more relaxed when doing so even when your pushing the volumes to crazy levels. SET Amps don't seem to work well on this and push-pull amps all depend on power and how its implemented. Still, After all these years, the OTL from Atma seems to reign supreme over other amps iv tried. This applies to any genre of music. Not just audiophile recordings.
This is the second 'zombie' thread that has been resurrected in the past day. I wonder what is in the air?🤔

In any case, @phantom, +1.
M-60s all the way! Getting rid of the transformers is a real game changer. SET and P.P. are just intrinsically inferior if you have the correct impedance speakers. I have owned all of these types and there simply is no comparison. I will say that the older CAT amps were the best of their type I had ever heard, but I still prefer the M-60s.