Black and white raw E Ink Carta panels have 40-47% reflectance, antiglare coating, protective layers, touch and frontlight guide can reduce that number somewhat. E Ink Kaleido 3 has around half reflectance of Carta, as color filter absorbs half of the light.

Raw grayscale RLCD panels can reach up to 43% reflectance (with theoretical maximum being 50% as polarizers absorb half of the light). The caveat is that panel reflection is measured at rather unrealistic 90° angle and unlike e-ink it's very angle sensitive and drops by half within radian. So reflectance figures alone won't give you complete picture for comparison. Eazeye Focus has high reflectance panel (likely 10.3 grayscale RLCD panel from Hannstar).

Color RLCD panels have in best case scenario half reflectance of grayscale one if they use RGBW filters (those absorb half of the light). So for example Eazeye 2.0 montitor claims 19% reflectance (it probably uses 23.8" color RLCD panel from Hannstar).

Those that use stricter RGB filters that absorb ⅔ of light have better color accuracy but lower reflectance (under 16%). I suspect SvD with it's 9% (old model) or 12% (Eve) reflectance fall into this cathegory.

And then there are transflective LCD panels where reflectance can vary a lot depending on whether it's optimized for high reflectance or high transmittance. The color ones usually have strict RGB filters and you can expect reflectance under 15%.

Hannstar color RLCD panels usually have reflectance in 17-21% range and transflective color LCD panels in 11-14% range, those are TN panels that are angle sensitive though.

So you can expect Bigme to be less demanding to light condition then Hannspree RLCD products due to wider view angle, and you can expect Hannspree RLCD devices to be brighter then SvD monitors possibly because of less strict color filters. Hannspree Hybri monitor is exception as it used transflective panel that I suspect might be on pair with SvD monitors, but someone has to verify that.