The differences in brightness and speed are already strong in black and white, but when you bring in e-ink variants with multiple inks per single cell the differences get extreme. The refresh rates get very slow, but the technology can manage to reflect most of the incoming light, while color LCD struggles to beat 10%.
No, they are NOT the same, either in underlying physical process or the resulting display characteristics.
E-Ink[tm] is electrophoretic, and works by migrating dark capsules across a charge gradient. That physical migration takes time, and is subject to degraded effectiveness at higher response speeds. This is why e-ink display quality increases with slower responses, and decreases with faster responses, giving a fundamental trade-off. Even given this, it's possible to drive e-ink at 16--60 Hz, and I've definitely seen the lower end myself. With only a slight degradation in display quality (slight ghosting), multi-Hz refresh is possible (roughly 4-8 Hz in my estimation). I've used that extensively.
E-Paper, a term I'm only recently acquainted with, is based on transflective LCD (liquid crystal display) technology. That's a distinct process in which the polarisation of a crystal matrix is directly manipulated under an applied current, which is an electronic process and correspondingly much more rapid and reliable than electrophoretic transitions. A key difference is that whilst the image on an e-ink display will persist indefinitely without power, an LCD screen requires constant, though low, power. "Transflective" means that the background layer can either reflect incident light (e.g., under bright indoor or outdoor sunlight conditions) or transmit a background light.
LCD response times range from ~60 Hz (16 millisecond) to 180 Hz (5 millisecond). There may be a slight decay time to the display, again, I've not seen large tablet-style displays, though the basic technology is the same as has been used in digital watches for decades, also the OLPC (one laptop per child) project launched in 2005, 19 years ago, and the Pebble smart watch. It's a mature technology.
The principle relative drawbacks of E-Paper relative to E-Ink are probably greater power consumption (though still lower than emissive displays), a narrower field of view (due to the top polarising layer), and difficulty viewing through polarised sunglasses for those wearing them. I suspect that the overall contrast of E-Paper is low (given the polarising filter which blocks half the incident or transmitted light, one source gives a 30:1 contrast: <https://www.newvisiondisplay.com/transflective-lcds/>), though E-Ink has a similar issue. Advantages are going to be faster response and no ghosting.
Color E-Paper probably has similar low-saturation properties to e-ink. You're not going to get vivid colour, but you can probably get some colour distinction in a desaturated / pastel appearance.
For large displays of the type suggested by TFA, E-Paper should be reasonably well suited, particularly in strongly-backlit transparent displays (e.g., windows or similar panels), and where mains power is directly available. Rapid and/or continuous updates (up to 180 Hz), for scrolling, animation, video, or other updates) would be readily supported.
Both E-Ink and E-Paper would be well-suited to daylit greyscale or multicolour (though generally not true-colour) displays, updating as much as a few times per second to every few seconds, suitable for largely textual / graphic displays without extensive animation or video.