I have 5 of these in my Escapade. they do a fine job. Yes they have slop straight out hte box but that disappears when they have power on them.
They're quieter and faster than my JR 591's both on 6.6V LiPePO4 packs. The S3004's are excellent value in my book.
They have certainly created a liking in me for Futaba servo's