Our patrol divisions are now almost all PI's with a handful of CVPI's and Tahoes. There are two PIU's but, only one of those are in patrol. I attended a Tahoe driving school and they had a PIU that they let us try out as well. The Tahoe wins hands down when it comes to room obviously. They run like a scalded cat and handle well for such a giant tank. The traction control/stability control is the biggest drawback for me. It needs to be dialed back some(a lot). The PIU had massive understeer which I haven't really noticed in the PI.Otherwise it is great. Not having looked at the numbers, it seems roomier than the PI too. The PI is liveable as far as space goes. It could be better though. The side to side room is cramped when there is only one Officer in the car. We sometimes have to double up Officers due to car shortages which makes it really tight. Getting in/out of the PI is not pretty at all. You have to twist and turn just right.
If I had to choose, I would take the PIU over the PI anyday. It's a toss up between the PIU and Tahoe for me. It is rumored that we are going all Tahoe. Our driving instructors want the PIU. Our equipment services manager was fired and our chief recently resigned for greener pastures so we'll see what happens.