I cant help you with the P IV, but I have a P III (2000) and it is an outstanding boat. Great rough water ride, fast, fishes great, etc. It can be slow out of the hole if you have a 2.5 L engine but the 2006 you mentioned is probably a 3 L so you should be fine. Unless the P III has the flippin deck extension that will be the biggest difference between the two boats since the P IV has the full deck. Let me know if you have any specific questions about the P III and Ill be glad to help you out.