2nd Update: Got the Beyerdynamic DT-250 in yesterday and was able to A/B with the HD600’s, and once again, was significantly underwhelmed, very “blah” like the AKG 553’s and 371’s, so all three go back to Amazon in the next day or so.
On a side note, I grabbed the cans that our guys use for our online mix at the church where I serve, just to listen to how they compare to my HD600’s. It is the Shure SHR840, that currently run for about $150. I was pleasantly surprised at the soundstage, instrument and vocal clarity and separation, crystal high end, meaty mids (but not honking), and tight, full bass (but not boomy). These significantly trumped these other 3 that I have auditioned. Obviously, these are not what most would consider “neutral” but they are very musical and enjoyable. In fact, I decided to give the top of the line SHR1540’s a test run, so I ordered a pair and they should arrive tomorrow.
They may not be as neutral as what I’d hoped, but I think the mids, where my guitar tone mainly sits, are close enough, and I can use them for general listening as well. (Another side note...my ears are probably leaning toward the Shure sound signal because I got a set of 846 IEM’s two weeks ago, and have enjoyed them thoroughly!)