You might as well. Nothing beats a brick and mortar if you can find what you are looking for. Heck they used to sell the V6 and 7506. They can also special order headphones that they don't normally carry. It's also nice to know you can just walk in for an exchange or what have you if you have any issues.
So I did a bit of looking about and I think it's between the Sony MDR-V7506/V6, or the Audio Technica M40X.
Looking for information, it seems I may like the M40x's better due to better durability, comfort, looks, and the whole two detachable cable thing which means if I mess up a cable like with my V6, I can just buy another and not have to recable anything.
I was also looking around for comparison in sounds, and found these videos.
https://www.youtube.com/watch?v=udLoAV7YmjA
https://www.youtube.com/watch?v=RWR7t-Vqoms
In both of these videos, I find out that I really dislike the HD280, and that it sounds like trash to me. Though, back on topic, in the first video I like both the M40X and the 7506, where the 7506 lacks a bit of bottom, but the M40X lacks that high end twinkle.
Then I watched this video:
https://www.youtube.com/watch?v=RWR7t-Vqoms
Here, the HD280 still sounds like garbage, but again back on topic. The 7506 sounds really good and strong, again lacking a bit of bottom end, while the M40X sounds almost worse than the HD280. WAY too overbearing on the bottom end and any mid or top end clarity is completely sucked out.
Now again, its just a video, maybe the video wasnt great or maybe they sound different in real life, but I just wanted to confirm;
Im not sure if you have experience with the M40x, but is the bottom end THAT overbearingly dominant that it ruins all other frequencies in some genres? If thats the case, im grabbing another pair of 7506s.