Does an upgrade make sense?

Given that you’re mostly happy with the sound now and what you’re looking for, I’d absolutely add a couple subs. Your speakers only go down to 36Hz (-3dB) so you’ll definitely get a better/deeper bass foundation, but you’ll also get an even more expended 3D soundstage and more solid and dynamic imaging within it. The improvements on offer here are not small. I recommend a pair of SVS SB1000 Pro subs because they’re small (about 13” square), will get you down to an honest 20Hz (-3dB), include software so you can dial in the subs from your listening chair with your phone (which is really nice), and a pair only costs as little as $1149 depending on finish. Plus they offer a completely risk-free, 45-day trial (including shipping both ways) so if they don’t work out for some reason just return them, so why not??? You can pay more and get more, but you may well find these are all you need for a significant performance boost on many levels. This one’s a no brainer to me.

https://www.svsound.com/products/sb-1000-pro-subwoofer

Hope this helps, and best of luck.

I will second the suggestion of dual subwoofers. I did this and it was a great improvement and really opened up and extended the lower frequencies. I don't like SVS subwoofers (long story) but REL and Rythmik are solid choices for audio. It can be tricky adjusting subs to your room, but when it's done well it's hard to listen without them.

In general, it looks like your system is fairly well balanced. But the streamer / DAC seems likely to be holding the rest of your equipment back a bit. @soix brings up one good possibility.

One of the great things about high end audio, is there is no limit to improvement. Typically I get to a level I am happy with and enjoy until the bug strikes, and then I slowly upgrade to the next level. Sounds like you may be there.

Typically the sequence is speakers, preamp, amp, sources. If you do this… do lots of auditioning before purchase. Invest no less than 2x.

But if I were you, I think you can get lots more out of what you have by upgrading your streamer and DAC to the next level first. This could bring you a good boost and enjoyment before rolling up your sleeves and upgrading the rest. You would enjoy more dynamics, detail, impact. I would recommend looking for a separate streamer and DAC.

To get a feel for what to invest, I would look at the cost of your amps and preamp and plan to spend about 2x what the average cost of those functions. So, if they were around $2K, then look to invest $4K in a DAC… then $4K in a streamer.

This sets you up to later do the speakers… which should be done with lots of research, as changing those will likely change the sound of your system significantly. Lots of auditioning before purchase.