Does matching components make a difference?

I presently have a Marantz sr5200 receiver connected to a NAD c521 cd player. I recently installed Blue heaven nordost interconnects as well as the 4 flatline bi-wireable speaker cables. My speakers consist of B&W 601s3. I was told that I should consider the NAD c320bee intergrated amp for my listening pleasure. I like Jazz. Iwas told that it would provide better detail and sound stage. Would this be a good move?
yes it would....your system should be killer.
I don't know about killer, but it should be an improvement over the Marantz receiver.
I use CDP Cambridge Audio 540C, Rotel 971 amp and B&W DM603 S2 speakers.
When I initially auditioned this set up - I was amazed. I could hear things I never did: sound was crystal clear, every instrument sounded live and I was immerged into music. I was thrilled and excited. My friends and my wife all said that it sounds very expencive and they love the sound. I have exceptional detail and sounstage and I never thought that I can get too much of it utill I was listening it for an extended period of time. It's like If it's too crisp and clear, my ears would get tired after 20-30 minutes.
I took my 540c cdp to several local dealers and compared it with others, like Rotel RCD1072 and used SONY 777ES and as much as they wanted to sell their stuff, they were amazed how 540c sounded. It was hard to tell the difference even on their HI-END equipment. May be Sony sounded little less forward then 540c on mid high range, but that was 5% difference and if you listen very carefully. Me and a dealer both prefered sound of 540c.
I listen mostly to jazz and instrumental music featuring soprano sax and clarinet (that's what I play), acoustic guitar, brass bands, accordion and some vocal groups.
My cousin has CDP and amp from Marantz and B&W 602 speakers and he mostly listen to jazz and it sounds great.

I don't know how much more pleasurable your listening experience will be with NAD, but it might be real killer of your ears. I think taht NAD is more similar to Rotel then to Marantz.

Personally I'm thinking of trying Marantz amp to smooth things around.
Get a demo of NAD from your retail store for a weekend and find out for yourself. That's what I'm going to do.