This fall I changed my speakers. Old speakers Martin Logan SL3 was changed to little older Quest. The bass is much tighter and the sound is "bigger". It's also very natural and transparent. I think that Jazz sounds better with the Quest than the new ReQuest. My Threshold T400 works very well with the  Quest. The Quest isn't the easiest speaker to drive,  but I haven't had problems. T400 works in pure class-A whole time so it really drives hot sometimes. Also the T2 works good with T400 as you can imagine. Best preamp. I have heard to date. It's very cool and neutral. One of the best even today.

I listen jazz mostly, but also rock/pop and blues. Also country goes very well. I own some 400 CD's and my evaluation CD's are followings:

•     Eagles Hell Freezes Over
•     Miles Davis Kind of Blue 
•     McCoy Tyner and the Latin All-Stars 
•     Diana Krall Love Scenes

System's Components
 

CD Transport:	PS-Audio Lambda
D/A Converter:	PS-Audio Ultralink 20 bit
Preamp:	Threshold T2
Power Amp:	Threshold T400
Speakers:	Martin Logan Quest
Interconnects:	Cardas Hexlink Golden 5C and some Monster also
Speaker Cables:	Cardas Cross biwired
Line Conditioning:	Tice Audio and Van Evers
Digital Cable:	Wadia

Miika's comments about his System:

AA: "Miika, how would you describe your system's sound?"
MJ: "The sound is very natural and transparent. Soundstage is very wide. Very balanced, lively, no problems."
AA: "Do you think there is room for improvement?"
MJ: "The room should be bigger with this kind of speakers, but they sound absolutely amazing also in small room. Acoustic is good." 
AA: "Have you got plans for upgrading?"
MJ: "Not right now, but the CD system I have to change someday. It's very good still but when new formats come, then there have to be with. Maybe SACD. Speakers will change to QuestZ one day. But I'm very satisfied right now with my system. "