Upgrade from Sony XA9000ES

Are you sure that it's the Xa9000 that needs more refinement (in my experience, it's a pretty honest player) and cleaner dynamics (whatever that means?) I have used the G08 and you would be moving sideways for the most part. You might try an Cambridge Audio 840c (really!-very refined but not the best dynamically) or an Ayre CX7e (a dynamic champ)The Wadia 860 is an excellent player as is the Ayre C5xe(a little more money than you've listed though.)
The bottom line is, you will have to go up the food chain to warrant spending the extra money to try to improve upon the Sony at its price point. There's alot of players out there that are more similiar in sound than they are different. You know, CD's are not the most refined and dynamic of sources in the first place. You also may want to look elsewhere in the system. You know, a lot of times, the better the CD player is at neutrality, the worse a lot of CD's sound. They are pretty damn flawed.

Thanks Bigtee and I agree about the inherent weakness in CD playback. I'm using a very quiet Spectral/MIT system and it allows one to hear the limitations of the Sony-as great a machine as it is. I would like even more refinement, detail and dynamics. The 860 is quite old. Are you sure it's equal to the Sony?

Yep, the 860 is a little better than the Sony actually IMO. The Sony was about multichannel SACD and even though it does have decent CD playback, it is certainly not the last word. The Wadia is more focused with a deeper soundstage, dynamics are better and it's smoother on CD's that allow for that to show through.
With all that said, I still don't think you are hearing the limitations of the Sony as you described. I think it's generated elsewhere in the system. The Sony is certainly good enough to pass a CD along up to its limitations. I have compared the following machines in my soundroom under the same conditions: Sony XA7es, XA777es, XA9000es, Arcam FMJ23, Ayre C5xe, Ayre CX7e, a couple of Rega's, Wadia 860 (I currently use an 861se,) Cambridge Audio 840c, a ARC CD3 and 3 Meridians, the G08, 508-20 and 508-24. Out of these, I still own the Cambridge Audio, the Sony XA7es and the Wadia 861se. I love the Sony simply because it has one of the best built transports ever used and sounds so analoque like. The Cambridge sees little use in a second system and the Wadia is my main player.
I can tell you this, all of these players are excellent with just slight flavoring differences. Nothing like what you are describing and desiring. This is why I say you are either hitting the CD wall and it's not good enough for you or something else in the system is at fault. I don't make comments lightly. I went through this CD stuff over the last 10 years and honestly, it's not good enough. The Wadia 861se is the best player I've heard except for some of the DCS stuff.
Also, certainly don't be afraid of older technology. It's built better and the technology is still relevent today.