whoops-maybe listing the components would help...lol
Unison Research Unico Secondo Integrated Amp
Cambridge Audio Azur 840C
Sonus Faber Grand Piano Domus.
sounds perfectly fine. i havent heard much from the unison, but i would personally change it to a simaudio or naim amp.
I'd ask what's behind your question? Is there some disatisfaction with the sound as it is - or compared to live music you have experienced? I've heard neither the Cambridge or the Unico, but from appearances, both seem to be good to excellent products. The Cambridge is well reviewed. As are the Sonus speakers. I liked them when I heard them...wish I could afford them.
So I think it gets back to what it is that you think you may be missing...or are you just unsure of your choices because others say that such-and-such product is better? If the system sounds right to you as compared to what you hear live and can play at sufficient volume for your tastes, there may be no need to make any change unless you just like getting new gear every now and then. On the other hand, if you hear something missing - lack of a realistic soundstage, some part of the frequency range out of whack, or so on, then maybe you want to look into some changes.
I'm going through just such an evaluation on some mid-90s British monitor speakers in which I replaced the woofers earlier this year without modifying the existing crossover. Is the sound really brighter, or were the speakers in their original design more "laid back" than they should have been? Ultimately, after listening to some universally-acknowledged "reference" CDs and records, as well as going back to some live music events, I'm coming to the conclusion that the newer woofers are an improvement over the originals and the speakers reproduce music that more closely approximates what I hear when I listen to live music. But that's not to say that I haven't had some doubts along the way, especially when listening to some CDs which I used to regard as decent sounding that have now been revealed as less than that.