Well, I just spent about an hour A/Bing my L2s with some of the new AKG 545s....in pictures online, the AKG looked like it had the full industrial, 'professional' look I was after (no orange!), with the 50mm driver perhaps giving a little more bass without compromising anything else.
Not much to say except that I decided to stick with L2s...despite my previous post about the L2s being of lower material quality than the L1s, they are still better (and cheaper) than the AKGs in that respect. Proper leather, much better quality cable, sturdier headband, comfier ear cups.
The part that really surprised me, is how can AKG use a 50mm driver yet create a perfectly round ear cup? No ear is perfectly round, so even though the cups look so much bigger than the L2 ones, with zero consideration and moulding for the natural shape of one's ears, the net effect is far less room for the top and bottom of my ears, which were both needing to be 'tucked in' to the AKG in a way:
My ears also touched the insides of the AKG, the pleather was a bit more scratchy, and of course being close backed my ears heated up much more quickly, but this isn't a negative against the AKG.
Must say that the headband of the AKG is more comfortable though, just due to the flatter, larger surface area creating less pressure per square inch. Now that I'm definitely keeping the L2s though (unless someone recommends another phone in this vein that sound almost like the L2s but are close backed!), I will still attempt to mod them by putting a bit more padding inside and under the centre-top of the headband.
Sound-wise, the AKG brings more bass and rolled off high end, which un-EQed does give for an 'easier' listening experience for the AKG for the type of music I wanted to investigate a bit more with it (metal, post rock, natural, foregrounded drums basically). However, the sound of a played bass was more present but really lost the clarity and subtlety that was possible to discern on the L2. This might be due to the open-backed nature.
Listening to a FLAC version of the 'Palms' self-titled CD through an L2 made me realise that the whole album is kind of focused around the bass riffs - which was later confirmed by me reading more and discovering that it is a side project of the bass player of ISIS, and he wrote the songs bass first - so if anything, the L2 led me to new discoveries in music just through its clarity! I didn't get any of the same bass clarity through the AKGs - there was more of it, but it didn't bring me any of this recognition.
Regarding the high end, the L2 can still be somewhat unpleasant for this type of music, but I figured that since I can make it 'perfect' for my tastes on my Sansa Clip + by just putting the bottom EQ up one notch and the top down one notch, why not just retain the headphone with greater possible sonic possibilities? The treble is there for other music where I need it (sounds amazing unEQed on the newest 65daysofstatic album, for instance).
As an aside, I had assumed the monitoring jack out on my M-Audio M-Track would give me the best results for listening, since it was in effect an amplifier for the headphone. Not so - its output is horribly trebly, which is what led to me overestimating the treble on my initial A-Bing with the L1. Through my Nexus 5, Clip+ and even the line out on my Asus Zenbook, the sound is very warm and well rounded. Avoid the M-Track for listening!
Having said that, the AKG is definitely probably 'easier listening' for more styles of music - somewhere in between the L1 and L2. But I'm prepared to fiddle with the EQ a bit for the sake of keeping my L2s, 'cause besides sounding better, they're an awful lot more comfortable.
Edited by pitchshifter - 5/19/14 at 12:23pm