Well, USB 3.0 will obviously give you better read/write speeds and if you have the Ultra or the Extreme cards, then a USB 3.0 card reader will really help. Otherwise, no.
Also, you need to check the prices too. Am not sure about Belgium (that's what your flag says), but currently in India USB 3.0 card readers are really costly and am just gonna use my 2.0 reader for now and get a 3.0 one when the prices come down.
Am talking about BRANDED USB 3.0 card readers like Transcend, SanDisk, Anker, etc., and NOT the shitty cheap chinese ones. Definitely stay away from those
These days both are inexpensive (at least in uk markets) so it only makes sense to go for a USB3 one. Backwards compatible with USB2, but gives faster speeds in supported devices. However I can't speak for other markets, so it's really a matter of checking.
Backlight can be one giant light panel with a diffusor, but recently there's mini/micro LED backlighting, where you can control the light level for smaller areas of the screen, to get better contrast and color range.