Yes and yes.
Diesel mechanic friend has removed his on a Peugeot (same engine) and noticed a difference.
Certainly more power. He says. And he should know.
He had to fabricate couple of bits.
Not sure of details.
Puts less (back) pressure on turbo, too.
I know no more...cratch:
Of the early mk3's, 2008 on, only the XTR 110 hdi has a dpf. On current models all the diesels have dpf. They are no trouble provided you do 50mph on an open road for a few miles fairly regularly to clear them out. I don't think mk2 cars have them.