I prefer original clears, but I find that they feel a bit too frictiony. I am also afraid of wear, with all this friction.
I would like to get the sliders lubricated to reduce friction, and thus, wear. I have read several data sheets for lubrication liquids and none has been as good (on paper) as RO-59.
Therefore, I would like to get them lubricated with RO-59. That would be my "favourite" mod.