Good news! I've found a local store in town that has at least a couple of the headphones I've been interested in. The DT770s are available in both 80 and 250 ohm versions as well as the M50s. These were the 2 I was most interested in hearing, I'm not sure how much else they carry (selection is somewhat limited) but it is enough to make me happy. I'm fine not hearing the AD700 since it's pretty obvious what it will be; tinny and flat sounding with very little bass but tons of clarity on detail. I know I won't enjoy them for recreational uses anyway but that they are top notch for competitive and that's all I really need to know. They would be a noticeable upgrade from my HTF-600 in terms of positional accuracy I assume. I'll be going out to try the dt770 and m50s after the long weekend though.
P.S. Canadian here. We don't have these "Guitar Centers" I keep hearing about to test things. The store I've found is also a guitar/instrument store though, called "Long and McQuade" does anyone know of any other places or ways to test headphones in Canada? I'm not sure if they will have a listening station set up but they have a solid full money back 30 day return policy. I will still most likely purchase online for cheaper from the US and ship to the border, drive across, and pick up. Unless there are better options.
When you test the headphones, try to find out what DAC and headphone amplifier they are using.