for me it is personal preference as far as the faded and the browns etc - i will say this
sometimes i have seen pretty obviously faked inserts which even though they are not natural they are temping because you feel it will dress up or dress down your watch - i have tried my best to stay away from these - for instance - if i see a brown sub insert and the fonts are yellow, that is a dead giveaway for me that it has been aged in an hour rather than over years in the sun. If the front is completely worn to death and the back is like it rolled off the rolex assmbly line i would stay away and i have actually been the victim of this from a VFR member who i will not name as i am not going to sling mud for this.
in any event, there is something to be said about naturally faded inserts and if you have a few bezels to pop them into, you can drastically change the look of your watch to what you feel like and for me i like to have the options -
on another note - i have also now been looking for a like new straight up black MK-1 insert and they rarely come up so i would say that the real pot of gold for me now.
it seems like the faded ones are always on the move and someone is hiding all the realy meat and potatoes like new fat fonts MK-1!
i will also say this - if someone posts an obvious faker on the marker i would be of the opinion that the post should be deleted and noted right away - that would help slow this down and protect a lot of people