Brief/early impressions of the Alpha Pads after about an hour of use last night:
I think I like them so far - there seems to be slightly more mids present, likely due to the toning town of the treble and bass regions. It's not a bad change, the bass still sounds rich and textured...perhaps a bit less mid bass, but I still felt impact when a song called for it. I found that I enjoyed the presentation with a flat EQ compared to my j$ Beyer pads, which I had previously been using with some minor EQ in the upper FR. I speculate there may be a few reasons for this: ear opening shape, driver angle and nylon filter. My j$ Beyers pads currently have very transparent nylon, even more so than the velour pads. I plan on swapping it out with a thicker nylon for the full comparison. I have not A-B'ed any of the other pads I have with the Alphas yet, just threw them on and went to town - I will plan on posting my impressions between Alpha/j$/pleather/velour at some point in the next few days.
Comfort, in comparison to the j$ Beyers, is higher for me. The leather is softer and the pad is more plush - I didn't notice any discomfort after an hour with glasses on. I can say the same about the j$ Beyers (and a leather conditioner could make them even softer) but the Alphas win for sure in this area, plus the build seems to be of slightly higher quality. Still, I think the j$ pads are a quality handcrafted item in their own right. This makes me that much more excited to get a pair of Mad Dogs. I will say that it's apparent the Alpha pad shape is made to fit the more oval shape of the T50RP, but still looks nice on the round HiFiMans. I was able to get them on the rings and onto the mount fine, but it took a little extra time and effort since they have more material on the back and I didn't want to modify them.
Sorry for the cell pics, but here they are on my HE-400. You'll notice the back end shape most in the second picture, where it seems a little flat - this is just the shape of the foam inside. It's not noticeable when they are on your head, though.