Anybody here upgrade from Chord Qutest DAC"

If you are ready to go down the rabbit hole, see this paper which describes the WTA algorithm and its effects on the reconstruction of analogue from digital signals...  https://www.moon-audio.com/content/pdf/chord/chord-tech-profile-hifi-critic.pdf

Also, note that the Qutest and TT2 convert DSD back to PCM internally...  Upsampling to DSD just breaks small signals, which some may like or dislike depending on your ear/brain/system/room...

With that ear 868l pre there is no sense going with the TT2...  Do you need an additional embedded pre in the loop? Keep the Qutest and add an Mscaler or go to the Dave...  You don't say what your streamer is...  Maybe an upgrade there would help...  I have a Lumen U1 mini with my Qutest and am very happy with the pair in my system streaming Qobuz Studio Premier...

Both the Qutest and Hugo TT2 have a 10 element pulse array design...
The Qutest has 49,152 16FS WTA 1 filter...  The Hugo TT2 has 98,304 taps...  Dave has 164,000 taps and a 20 element Pulse Array...  The MScaler takes either the Qutest, Hugo TT2 or Dave up to 1,015,808 WTA taps...

There is some software available with/for Roon that can Upscale similar to the MScaler called HQPlayer...  I think there is a free trial for it...  Although not exactly the same filtering as WTA it might give you a sense of what a bunch more taps might sound like with your current DAC...

Also, if you can do a little software building there are mods to SoX and FLAC which allow similar upscaling and filtering capabilities for free...

Other non-Chord DACS will not have the same timing precision which may or may not be a good thing depending on your ear/brain/system/room...  Good luck in your quest...