Both are lovely, but I slightly prefer shade :)

Flats are usually better for artists so they can get the colors correct ^o^

Really it doesn't matter

While it doesn't matter, flat does work better as a reference for other artists, though shaded tends to have then little bit more to make it look nicer

It's usually something other than the shading that makes an adopt pop for me. Shaded would look nicer, but since chances are I'm going to use the adopt as a reference for future art it is not essential.

I like both, but I prefer that if I have a shaded version that a flat is included with it... Only because it makes it easier to color pick and also be certain I don't think something shaded is meant to be the design.

From a selling point... The shaded option LOOKS fantastic (depending on the artist) but like others said, the flat is needed so an adopt you sell can act as a ref for others.

If you're able, i would say display a shaded piece and save the flat too. Send both out to the purchaser so one looks pretty and the other can be used as a comprehensive reference sheet

Shaded are prettier but..artist prefer flats to work with as it makes it easier to grab the proper colors.

Both are wonderful but for references usually flat is better for artists to reference color palettes

Flat is much better, so artists can use it as color reference imo

I definitely love variety in both! It gives everyone something to chose from if they have a preference ^^ <3.