Yes, I use Derby in my EJ...it is a very mild blade and works great for me...i do not have a heavy coarse beard. Since I have only been wet shaving since Christmas, I still have a selection of samples. I keep going back to the Derby. The Gillette 7 O'Clock is a sharper blade and the first two shaves are great but then I start to get a few nicks and weepers and need to change blades. I have not used Dorco.
I tried a travel tech for a short time. More of a novelty for me—I found the razor laughably small when trying to use it to shave. It will, of course, do the job as well as any regular sized Gillette Tech, but one must get acclimated to the lilliputian handle…
I found that having to pinch the handle right under the head of the razor made me want to apply pressure, since I didn't have the counter balance of a longer handle. Once I figured I had to really watch how much pressure I was applying, like Kevin said, it shaved no different than its longer handled brother.
I just picked up one of these (1966, so it's a year older than I am!) in near mint for $8.00 plus $3 shipping. Sound like I got a decent buy? (Yes, I know a bargain is in the eye of the beholder. But empirically, a good deal?) With the timing of the arrival compared to the other one I have bought, this one may actually end up being my first vintage.
Just the razor but it's in great condition. Wanted one with a travel kit too, but got outbid in the last 30 seconds. :/
This is my '62 I got back in 2012. They are nice razors. I think you will like it. You can get one at a good price if you are patient.