MXR gt-od

both the classic od and gt od go for around $100 new and $50 used so not sure what you mean. they are also definitely not the same pedal, the gt od sounds much better for metal imo.
The Classic OD was a Guitar Center exclusive and was about $40 new from GC when it was around. It seems people try to pass it off as some sort of fancy edition and try to sell it for what it was going for new or even more in eBay.

The white Classic OD came stock with the switch flipped to Zakk Wylde mode. The fatter, middier, louder setting is GT-OD mode. There was also another version of the Classic OD in green. I'm sure you'll find them a lot more similar to the GT-OD if the internal switch is flipped accordingly.

Not sure about the Custom Shop GT-OD, but the later non-CS GT-OD and the Classic OD are the exact same circuit board. All of them have "ZW OD" or something like that printed on the board.
 
https://dl.dropboxusercontent.com/u/2973685/ODshoot.rar

I included the GE-7 which is not an OD but still a great way to shape:boost the incoming signal. I'm not personally shooting for "transparency" but for different tonal characters the same way you'd change pickups.

I used the green channel of the 6505 for once. I figured it would be easier to hear the differences since it's less compressed.
The GE-7 sounded pretty cool. Had a cool bite and was not as compressed.

I prefered the Maxon to the MXR in this clip by a hair, but they had a similar vibe going on. The hefty lower mids of the MXR come in handy with some thinner-sounding amps, IME.

Funny how the emulation came out a bit fatter than the actual Maxon.

I know the East River Drive is EHX's TS, but what's the Glove supposed to be based on? Seemed fatter to me than all of the others.