DACs are very much a solved problem regarding our thresholds of hearing. D90SE is and should be considered a great DAC but it 'sounds' the same as many inferior/cheaper DACs since their performance is already beyond what we can make use of in a normal listening scenario.
With amps you basically have two routes, embrace the tube sound or go clean solid state. ASR is all about engineering prowess and the majority here are going with the latter. That way you have a clear, objective way to approach gear: go for the transparent, neutral option.
If you want to try that for a change, the Benchmark is a no-brainer. A couple of other great options are Hypex NC502MP or Purifi based amps.
I'm not familiar with your speakers but in general speakers (and their room interaction) are the weak link and where the big audible improvements are made. Digital room correction, optimal speaker and listening position, (multi-) sub integration, room treatment..
IMO YMMV etc.