I had a top level Warrantywise policy on my 4200. I made two claims during my ownership. One for a broken reverse lever and one for something else that's slipped my mind at the moment. On both occasions Warrantywise were excellent. They liased with the garages, agreed the repairs quickly and settled their bills immediately. In fact, Bill McGraths actually commented upon how efficient Warrantywise were compared to other warranty companies that they had dealt with.
Proof is in the pudding and I took out a Warrantywise policy as soon as I bought my Quattroporte. At about £1500, it is expensive compared to some other policies. But, it gives peace of mind and I believe is worth the outlay.