IMHO, Classe. I feel Classe should be compared with the top brands. I would class Bryston with the Acurus, Aragon, Sunfire and McCormick products. I have a full line of Classe products and feel they spare no expense when it comes to audiophile quality manufacturing. Their sound to me is rich and lifelike. Their "real world" pricing puts them in a class by themselves too. Depending on what you listen to, I can tell you that you will find their products warm but with a dead quiet background. My friend has a Krell intergrated amp with a CD player (Krell). He came over to my house with a CD by Lalo Schifrin . We both have the same pair of speakers, but he noticed he could hear more detail. The odd cough from the audiance, finger tips playing the claranet and there was more depth from my Classe units. How could that be from a company that makes warm tube like products? Great engineering. I know you are comparing the Classe to Bryston, also I have never heard the Bryston products, but I can tell you this...You won't be dissapointed if you go with the Classe. Not endorsing them and don't work for them.
I own a Bryston BP-25, and it is an excellent product. Sonically, it is very smooth, yet detailed, with absolute silent operation. Lots of air around instruments, wide soundstage, nice imaging. It is solidly built with useful features. 25 year warranty is certainly a plus, but you'll probably never need it. If you do, service is excellent. I broke one of the balanced output jacks (don't ask--it was dumb), and they had the repaired unit back to me in one week, total time.
I was looking at the new Bryston pre-amps (I used to own an old 0.5b) and the Classe, but in the end I went with the Musical Fidelity A3cr pre-amp. It's only $1500 or so new, but it compares really favaorably with any of these other units. It offers amazing quiet, phenomenal detail and imaging, and a beautiful warmth. You should check out the Wes Philips review on Soundstage.com. I was actually not very happy with the Classe units I heard. From everyone I have spoken to they are love 'em or hate 'em units, so if you go that way make sure you hear one first. The Bryston BP-25 is excellent, but a little colder than the A3cr and no quieter or more detailed. If you need home theatre though, the SP-1 is a very fine unit.
Bryston has a punchier house sound. Classe's is more delicate. You seem to like hearing the details, which would suggest the Classe. However, a Bryston preamp might provide some synergistic benefits paired with your 4Bst. Also, you may lose much of a Classe preamp's delicacy after passing through the 4Bst. Recommend borrowing both and trying through your system.
For 2ch listening just upgrade the receiver to the Bryston SP-1. It is great for 2ch listening and functions as a home theater processor. It is upgradable and has their same 20 year warranty. I don't agree with placing the Bryston in the same class as Acurus. I own an Acurus amp also, and the Bryston blows it away.
I would go with Bryston, partly for the synergy with the 4Bst (which I've owned and I feel is a phenomenal amp for the price, much less colored than any Krell I've ever owned or heard, and in a completely different league than the Acurus and Aragon amps (which I've also owned). I think the BP-25 is nearly unbeatable, and if you ever do decide to resell it, it will retain a lot better value than the Classe stuff. The 20-year warranty speaks for itself.
I have a friend that has Classe and has had nothing but trouble with Classe. He has sent his integrated back 5 yes five times in the last two years. He has had no problems with any of his other components. They claimed to have rebuilt it each time. His name is being withheld since he wants to dump the amp and buy Bryston.
I owned a Bryston BP-25 mated with my 4B-ST amp and there was synergy with this match up. However I did swap out the BP-25 for a tube preamp (Rogue 66) and in doing so gave up some of the detail but realized the warmth I was looking for. As a SS preamp the BP-25 is hard to beat and ya gotta love that they hold their value and offer the best warranty in the biz!
My whole system is Classe and because I never heard Bryston I cant comment on what sounds better but Classe has a great reputation for quality. They completely covered two repairs including shipping that were completly my fault and not covered by warrenty. One was even a piece I bought used. I have delt with many manufactures and in my opinion Classe offers the best customer service I have seen in any product. Audio or not.
I've often wondered over the years why there always seems to be so much Classe equipment in the used market, but beyond that observation can make no other comment, since the only piece I've ever owned was their Model 3B (I think that's it, but it's been a while.) pure class A amp that was rated at just 25 w/ch, generated tremendous heat, weighed a ton, drew enough current to dim the lights, and fried some of the wiring in our turn-of-the-century house. God, how I loved that amp on my Quad 63s!! This was back in the mid '80's, but shortly thereafter they went to an entirely different, i.e., much broader based, marketing approach with an all new, less esoteric product line.
Oops, sorry for the digression, but I'd recommend the Bryston BP 25, or, if you don't need a remote, the 20 for even less money. Or, since Bryston offers a 20 yr. transferable warranty, why not get really cheap and buy one used? What Bryston gives you is what a component should: Accuracy. The music should come from the software, not the electronics.
Maybe I can chime in as well as I've had 2 Bryston 3B amp (100 Watt)/0.5 preamps for the last 15 years and in just the last 3 months have switched over to a Classe SSP-25 pre/pro and CAV-75 6 channel amp. Soundwise I'd have to say that the Classe is the clear winner - much smoother, more detailed, and yes "quicker". Keep in mind that the Brystons are 15-year-old models and I'm sure (hope) the newer ones have improved. Nobody can beat the Bryston service however.
I have listened to Bryston 3BST, 4BST and 7BST monoblocks in a friend's system. Also, I auditioned Bryston prior to making a purchase. In the end, I chose to go with a Classe CA 300 amp and CP 47.5 pre-amp. In my experience, both Classe and Bryston deliver the goods, and I have a good opinion of Bryston. But to my ears, the smooth, mellow sound of Classe is more appealing. I just love listening to jazz horns played through the Classe.
Points to consider: 1. I believe synergy between components might be an issue. I use all Classe gear, for example. 2. Bryston has an excellent reputation (Stereophile rates Bryston Class A and B consistently) 3. Your mileage may vary. What sounds good one person might not sound good to another. I've auditioned some awfully expensive gear over the years that just didn't sound good to me.
I've come to similar conclusions on my own about Classe gear. Bryston is an outstanding value but not in the same league as Classe. Someone asked why there seems to be so much used Classe gear on the market. It is my belief that this is because Classe has been around for such a long time and their gear is very popular... and their gear is very popular because of the excellent sound, yet Classe is reasonably priced and competes right up there with the mega buck brands. Just my humble opinion.