DAC upgrade?

The guy at soundnews.net does nice reviews IMO and has reviewed both as well as the A22 and may have even done some comparisons between them.  Again, I do believe you’ll get some improvements, but changing DACs isn’t like changing speakers so whether it’s worth it depends greatly on how casually you listen.  If you sit down to listen to music this could be worthwhile, but if you usually listen while doing something else it’s probably not.  That’s about the best way I can put it.  Hope this helps, and best of luck. 

@soix Thanks again for your responses. I would definitely say I am more than a “casual” listener as I like to sit down and will listen to an album start to finish. I don’t, however, find myself critically listening when I am listening to an album.
Regarding one of your other comments, would my personally ripped CDs into lossless FLAC/ALAC sound just as good, if not better, than streaming cd quality tracks from Tidal/Qobuz?

Ok, given you sit and listen I’d have to say I think you’d appreciate a better DAC in large part because your system is revealing enough to clearly show the improvements IMHO. Deciding between the A18 and the D90 is a tough one as they only seem to differ slightly sonically with the Gustard being a touch more detailed up top while the Topping may posses a tad more warmth in the mids, so I’d make my decision based on which slight bias would match better with your system and tastes. Looks like you can return the A18 if you buy from Apos, and if you can also return the Topping I’d try to demo them both if you can do it as then you’ll know for sure.  Frankly, they both seem so good I don’t think you can make a wrong choice.

For streaming quality I’ve found the Qobuz 16/44 tracks overall to be comparable to spinning my CDs and their hi-res, not surprisingly, to be better. Put it this way — I haven’t spun a CD in over a year since getting Qobuz, and I’ve had more fun finding worlds of new music than I ever had listening to my CDs. Not sure that answers your question, but that’s my experience FWIW.

On my opinion, Gustard A22 is much better DAC upgrade option for audiophile, vs A18. A22 has much better power supply, solid heavy enclosure, dual AK4499 DAC, and NO OP-AMPS in sound path, using discrete class A driving stage instead. It works well for me, and most of the time it drives amp directly. 

Sounds like I have some further research to do; although suspect either the Gustard or Topping will provide better sound quality than what I have.
I suspect I could open up a whole can of worms when asking about Tidal vs. Qobuz. The consensus seems to be Qobuz for sound quality, Tidal for content?