I am looking to upgrade - looking for advice

There are a lot of ways to go here and budget and component matching are going to be extremely important. I agree with @jasonbourne71 ​​​​, your speakers may be your limiting step right now. B&W have a strong house sound and that sound, to me, is on the extremely revealing/bright side. Many B&W owners temper this by using a tubey sounding tube amp like a McIntosh. The biggest single contributed to how your system sounds is going to be good speakers. I might spend some time going around and listening to different speakers. Don't just listen for 5 minutes either, listen for as long as they'll let you. Speakers are like TVs at Best buy. They turn the brightness and contrast all the way up on those TVs to make them pop on the wall, but when you get them home you realize this hurts your eyes and adjust the settings. The brightest most detailed speakers will pop in the store but then when you return them home you may realize they are fatiguing. I say all this to say that make sure you have the right speakers before you go spending thousands on electronics that will never fix the problem. 

If you find you do like the speakers then what is your budget? I agree that changing your preamp would be the next step. There are lots of great units on the used market and that's where I'd look to get best bang for buck but first need to know how much you want to spend. 

Speakers are the most flawed devices. Yet offer the biggest improvement when changed. None of them sound exactly like  real instruments and voices! Not even the $200K Wilson Chronosonics. With speakers it is often what you can tolerate over time. We all hear differently and have preferences for different aspects of frequency response, timbre and dynamic range. So the marketplace provides such a variety of speakers - from small shoe boxes to towering monoliths!

I agree with jasonborne on this one. If you stick with your current sources as is, it is very unlikely that a new set of amp/preamp will make big improvements. BTW, I love my A21+ amp.

I’m always amazed how many are devoted to the concept that spending (significantly) more money equals improved SQ. We all tend to agree that SQ is a perceptive concept, not an empirical one. Yet many espouse that the bigger hit to your credit card will automatically result in jaw dropping improvements. I respectfully and adamantly disagree. 
 

No one can tell you what to buy. Or what to spend to achieve your objectives. Only you can. Heck, most will suggest you buy what they have. Bottom line, your best bet is to try equipment of interest and decide for yourself. But don’t let the price tag be a basis for anticipated improvement. 
 

Sorry for being a grouch this morning. We ran out of coffee so I’m stuck with decaf. 

What is budget? 

Would you consider an integrated amplifier? 

Vincent makes a tube/SS hybrid integrated that has a DAC onboard. They also make a hybrid preamp that mates with the SP-332. I have owned a Vincent integrated and it sounded wonderful at the price point. Would sound less clinical, not as dry with more air, than the Rotel gear. Great soundstaging.

Another thought, given that streaming is your main source you might think about getting a DAC to pair with the Node. There are threads on this forum that address that option.  If your cd player has digital out the DAC could also serve it.

If you enjoy your B&W speakers keep them. There is much you can do to get more out of them.