Rather than a better or worse experience it's a totally different experience - IEMs and headphones are completely different presentations so I'm not sure how to answer this question haha

I own an XS, demoed the B2D, have not A/B'd both together - I would expect the B2D to give you more detail, however the XS's soundstage is just going to be just one world above - XS's soundstage height & imaging is slightly above average, soundstage width however, whew!

I do not own any of the DAC/AMPs listed nor do I care for measurements (I only care to enjoy my music) so I really don't know whether your current dac/amp will do or not - my assessment is that the XS is moderately challenging to drive - not super difficult nor temperamental, so I am guessing you should be OK.

Regarding cables, for the Edition XS, I would highly recommend getting a new cable - while the stock cable is doesn't cause me any actual usability issues (it doesn't tangle/fray/etc.), one inconsistency/problem the Edition XS is notorious for - different stock cables have been measured to have wildly different impedances. I personally use a Tripowin GranVia.