Where should I concentrate my upgrade dollars next

I would swap the Jolida. Not that it's not a worthy piece. The Slim is not going to change. Rotel you hardly use. The DAC is another candidate for change. The speakers would be another option...but you said you were satisfied with the power you have. So, if you are content with output power...change the DAC. If you want the same power performance, but would like the biggest overall change...change the Jolida to a SS integrated like the Exposure 2010S. There is one for sale here. A great piece . On the other hand, a 300B would work well with those omegas. If you are content with the overall system, but prefer a less overall impact, say a slight lean towards musical, change the DAC to a tubed one. The MHDT Paradisea for example. I'm trying to keep you in the same ballpark.

i would identify specifically what is not "doing it for you" in your system so as to id the weak link in the chain and upgrade that only. Also are you sure you are not upgrading just for the sake of upgrading or because you are bored with your current sound and want something different? That's fine if that is the case but then you would at least know that's why you are doing it and that would open up the field to any of a number of your components that can be subbed out.

It would be nice to know where you want to go with things sonically, and your $$$ for it... as all in your system could be stepped up if you think about it.

More euphonic, more resolute, sppeed? Volume? Bass? just more music in the music?

That said, anything in the cottage system is suspect.

But for more order as to my own philosophy ...

I like power cords. Once you get them, you got them. When gear changes, you've still got the pcs. Just by moving about some of my own pcs, I can alter the presentation, sound, and tone to lesser degrees.

I like what can be done with tubes too. Rolling tubes can make for significant steps upward... or sideways... which isn't always a bad thing. Again, once you've gotten those other tubes... you've got them.

I'm also big on sources. Sources & preamps. Not that I have a lot of them, but feel and have found out just how key having the begining of the signal is, and keeping it intact thereafter.

That DAC seems the logical spot for change to me primarily. shortly after, try experimenting with a better digi IC & power cable.

Past those, another preamp. Both moves however should be upward steps and point to your intended goals.

Lastly I would exchange the amp if after rolling some tubes the sound doesn't suit me enough.

Along the way do consider what stepping up power cables can do for you... sometimes it can be an immense step up... I ususally see fit to address both ends of the rig with more of an investment, with the midddle (or preamp in my case) receiving a bit lesser pc attention.

I mention all of this as I get the imp you don't wish to swap out the squeakers yet. If squeakers are in play, aiming at certain ones will tell you which way to go with the amp choice. That amp to squeaker relationship is integral.

Remember whatever is lost upstream, can not be regained downstream.... consequently, sources are mighty important. In a pc based sound system, the DAC is as a source. Add in 90% of your playback is personal confuser oriented, start looking into DACs.

Knowing something of that amp, maybe just adding a small good sub is all you need now too.

IMO do not spend any money on more tweaks. (power cords, cables, etc.) Spend it only on the actual equipment (until the stuff is the best you could want)

Room treatments