The Absolute Sound as compared to just sound? re: Headphones.

To my dismay some of the "professional" reviews are using their phone or some low-fi device to evaluate a set of headphone's performance.

I feel your pain brother and couldn’t agree with you more.  A little while back I did some research looking for some decent ‘phones for a friend and found it extremely difficult to weed through all the crap out there to find anything halfway credible.  In fact, as a result I’m now starting my own head-fi review site to try to provide useful reviews coming more from an experienced audiophile perspective rather than from a headphone “hobbyist” turned blogger who struggles to convey what they’re hearing because they have little to no foundation in what good sound truly is.  Sorry if that sounds arrogant or condescending, but that’s how most headphone reviews out there come across to me.  (BTW, big Car & Driver fan here and point well taken on R&T — good analogy). 

Anyway, I think posting what type of sound/performance characteristics you’re looking for here along with your budget might be more helpful than trying to parse through all the detritus that exists out there.  FWIW. 

Do you have a budget in mind, and do you have the capability to stream music through Qobuz, Tidal, etc.?

Since you’re a Maggie fan I’ll highly recommend the planar HIFIMAN HE400S that I actually own, but they are open back and leak sound that may bother someone else nearby if that’s a consideration.  They’re normally $299 but currently on sale for $249 and I think they’re well worth stretching your budget a little for.  They’re very detailed but natural and open sounding (like Maggies) so there’s a lot of “outside the head” imaging going on and the headphones disappear as a sound source very well also — which I love.  They have the added benefit of being fairly easy to drive, especially for planar ‘phones, so you shouldn’t need a separate amp to get them going.  That said, and like all good equipment in audio, they will scale up with with a better amp and source so you can kinda grow into them in stages if you like.  That’s what I did and am extremely happy with my current setup that consists of streaming hi-res Qobuz through my iPhone or iPad to (via an Apple Camera Adapter) an Audioquest Dragonfly Red portable amp/DAC into the 400S.  BTW, I highly recommend Qobuz that you can try for free, and it’s only about $15/mo. if you decide to stay with it — best 15 bucks I spend every month as I get both hi-res sound and the ability to find worlds of new music on a daily basis (rarely bother spinning discs anymore).

Anyway, that’s just one recommendation FWIW and hope it’s at least somewhat helpful.  Best of luck in your search.