Pros: Soundstage, detail, and balanced sound that isn't bass shy.
Cons: none that I can find. Difficult to find.
Read all the reviews here on headfi and you'll get a very accurate idea of what you'll hear.
I have been buying portable earphones since the early 90s, mostly Sony and their $100 models.In the past several years I've gathered Klipsch S4(great budget gear) then the V moda M80 for my first headphone and its great in a warm smooth way with plenty of great bass for my taste, and because it was on sale the Klipsch X5 which opened my eyes with the astonishing detail it relayed, and this made me want an over ear that was somewhere between the M80 and the X5. I wanted detail but also deep bass and something neither had, soundstage!
Like many, I was looking around the $200 level and the real contenders were the AKG K550, Beyer 770LE and Quart 8.35D oh and these of course. There just wasn't much written about the 8.35 and there were issues with comfort and soundstage so that was scratched. the Beyer was sounding appealing but it has scooped mids and harsher highs scratch. The AKGs have got real good reviews but that would depend if your head was huge because they are big and the bass, which isn't strong in the first place , disappaers without a good seal. I chose the Soundmagic after reading almost no negative feedback except one guy in Portugal that says they have a upper bass suck out, so I went for it.
These are much more neutral than warm like my M80s which was what I wanted because while warmth is smooth and all I wanted to hear more fine detail and these deliver without being harsh at all. They are actually quite smooth considering their sound. The soundstage is huge compared to anything I've owned. Having everything seperated only aids in being able to detect finer sounds and layers. I read allot about how the M80s have "polite" treble and I can understand that description but frankly they need more sparkle and with the HP100 you get that. I can clearly hear the splash and crash of cymbals whereas before they were buried behind the warmth. The mids are neither forward or recessed and are crisp and sharp and not at all interfered with bass. The bass is awesome. Listenig to a song that isn't bassy and you get the impression they wouldnt be bassy because these are a bit on the clinical side, but the moment bass enters it is there in great proportion and again in a very detailed manner. You can here exactly how the bass sounds rather than just a oomph. Somehow these manage to deliver very deep bass that makes electronic music fun, literally vibrating the cups on your head!
Bottom line is I am very happy. I think its difficult to pull off cans that have this kind of detail yet still can have incredible rumble. This is what I wanted and I am very pleased. Oh and the build seems solid with plenty of comfort and adjustments. They feel solid and the pivots aren't wimpy. The looks are neither here nor there for me as I buy them for sound, besides my M80s will be my portables. I'd put these against any headphone of this class.