Classe DR-15 amplifier compared to Classe Dr-9

I have two Classe Dr-15 amplifiers used in bridged mode and was wondering if they compare favourably with the Classe DR-9's. I find the Dr-15's to sound really good, not as fast as today's amps but otherwise very little to complain about. If the DR-15's compare favourably to the Dr-9's I may forget about replacing them. Any input would be appreciated. Thanks.
Classe DR-9's/15 I had both amps. The Dr-9 amps are more refine to my ears and with more weight and growl Than the 15. the Dr-15 is a later design/product and has no association with Dave Reich the original designer of the 9 and once owner of Classe. I am sure there are memers who see and hear it another way?
You say"not as fast as todays amps".I wonder if tomorrows are faster than todays and so on where we'll be in say 25 years.I wonder if one day they'll stop going so fast.I love this site,where else would we go with these observations?Sometimes I feel like science-fiction is becoming the norm...thanks for that,cheers Bob
I forgot to apolgize for the hijack of a legitimate question of which I have no answer,thanks,Bob
I was a Classe dealer for many years and this is how I remember it:

The DR-15 was indeed designed by David Reich AND Glen Grue and was a class A/B amplifier. The DR-3, DR-8 and DR-9 were pure David Reich designs and pure class A. They had a darker, warmer, more mellow sound than thier class A/B brothers.

I had a pair of DR-8s running mono on a set of Apogee Stages and it was one of the most beautiful sounding systems I have evr heard.

Not sure if I would swap out a pair of DR-15s for DR-9s? I think it's probably a side step and not an upgrade per say.
The Classe DR-8 and 9 where not pure class A designs but a/b, the DR-3 was there only pure class A design. Had a DR-9 for many years and it was a fantastic amp, only bettered by the DR-3 and only if you had speakers which did not need large amounts of power.Great amp for Quad esl 57s. Sorry I can't answer your original question, just wanted to clarify the misinformation regarding the DR-8 and 9.
I found my Classe Twenty Five more dynamic and open than my Classe DR-25.
As Mofimadness suggested it may be a side step rather than an upgrade to replace the Dr-15's with DR-9's. I'm using the Dr-15's with Apogee Stages and a passive preamp. There appears to be a real synergy happening and I'm very pleased with the sound. I was told earlier that Jason Bloom used the Dr-15's in his development of the Stages though I can't confirm this. I think the Dr-15 was the last amp to contain Dave Reich's signature, alongside Glen Crue's. The speed issue I mentioned earlier has been noticed by other owners of DR amplifiers. I've been told it's a result of using four large capacitors instead of multiple smaller ones that Classe subsequently used.
Majicjazz...according to the brochure in my hand , the DR-8 and DR-9 WERE Class A amps up to about half their output,(70 and 90 watts), respectively then switched to Class A/B. Sorry for the confusion.
If I remember rightly the DR-9 was designed as an A/B design to compete with DR-3s in sound without the high price tag of class A. The DR-15 is more of a Glen Grue designed amp using Dave Reichs signature as a selling feature.
To the person who stated that the Classe DR-3 was the only pure class A amplifier designed by David Reich: David also designed the DR-2, DR-3B and DR-3 VHC (short for very high current 45 wpc pure class A amplifier). All are now highly collectible sonic works of art. In the class of early Mark Levinson gear like the ML-2's but far more reasonably priced.

The only draw backs to these early Classe amps are the tremendous heat that they give off and the large amounts of current that they use -- they are very inefficent designs, yet sound very much like good tube amplification.

Back in the early 1990's I owned a DR3-VHC and later a DR-2.
Both were built like tanks; beautifully engineered and constructed.

The DR-9 is an excellent amplifier; also built extremely well. However, it is not a pure class A design and probably gives up just a bit in the way of sound quality as a result of it. Yet, it is still a superb piece of hi-fi gear. Had I not owned the aforementioned DR's (hard acts to follow) I would be even more impressed with it.

As for the newer Class A gear, it's still very nicely built. However construction is now more to a price point than it was back in the early 1980's, when David Reich made his company famous, by building the best amplifiers he knew how to. His creativity in the early Class A line of amplifiers and preamplifiers still draws the attention of hi-fi enthusiasts the world over. His amplifiers were (and still are) that impressive.
Lornoah, what do you mean about "as fast"? Can, or any of the other guys on here describe this statement in more detail?

I've heard the term used and would love some clarification.

Sorry for the late reply. I was using one Dr-15 to drive Apogee Stages and found the resulting sound slow and sluggish. I was also using a passive preamp so there may have been an impedence issue. Buying a second DR-15 resulted in a faster sound and more true to life. I experimented with short low capacitance cables and this also improved matters. I'm at the stage now where I'm satisfied.
The thread is from quite some time ago, but adding some input for those who arrived here through an internet search looking to research or purchase a DR-15 or DR-9. 

Adjectives such as "speed" and "fast" when discussing amplifiers, speakers, or cables seems to really be about how well a system accurately captures attack and decay:  the key stroke on a piano or the hit of a drum have an attack at the strike and a decay in the sustain -- an audio instrument that accurately manages these attributes is one that doesn't turn muddy, muffled, or unfocused at these sonic junctures.  In other words, an amplifier should have enough power to expand and contract the speaker fast enough to capture each beat of a drum solo; yet, the speaker needs to be fast enough to accept these changing demands from the amplifier and respond accordingly.

When all goes well, amplifier, speakers, cabling, even a stylus should all together have enough synergy and balance to maintain the integrity of the original instruments in play.
That’s a good way to put it.