HI,
I have found that Miller's Diesel Eco-Max, along with using premium diesel has transformed my XF-S 3.0D since I bought it last October. Quieter, more responsive, more economical!
I occasionally do a very long trip to Ireland, but apart from that, short local trips. In the 10K miles I've done, I've only had one "Regen Needed" message; quick blast around (a bit of) the M25 and it went away.
Obviously, I don't know if that would have been different if I didn't go for premium diesel and the Miller's, but for a car that's lucky to do 100 miles a week, apart from a long one every couple of months, together with all the DPF problems I read about, there must be something in it!
I'm no expert on the relative merits of one additive over another, but for the future, I'll stick with Miller's.
Just wish I knew if it's Miller's or Millers 🙂
Cheers,
Jon