I use it with great success on the X3. I use it periodically about twice a month. I don't eat in the X3 nor does anyone else. I use care when getting in and out of the vehicle as to not squish the side bolsters out of shape. Before conditioning the leather, I use a vacuum and go through the seams to get rid of dirt/sand/particles that might get caught in there.

And the leather still looks and feels new after 48k miles. Indeed it's in better condition than our CPO 325i sport, which has 8k miles. I know it's a PITA to adapt to leather and try and keep it clean. But hey I'm proud of it!

To answer your question, yes it is about time to detail your leather.