I had a 2.4 petrol and have a 2.7 TDi (so the later intercooled model) now. I'd say there's not much in it between then on the road, the petrol is definitely quicker up to 60 or so mainly due to fewer gear changes cos it will rev a lot further, 1st is actually a gear in the pertols not just something to get you moving with.
Diesel probably has it cruising on the motorway as the extra low down torque means you can hang onto the gears and not change down on the hills as much, not that either are bad for that but I travel over the M62 occasionally.
Petrol uses a bit more fuel but diesel is more expensive anyway so theres not a lot in that.
Offroad again theres not a lot in it, you just need to use a lower gear in the petrol at times, but I found the pick up useful at times, non of this waiting for a turbo to spool, instant power.
Whatever you buy, prices are well down at the moment, an early model with rectangular lights should be under £1k unless very late and vvgc and a later model with twin round lights shouldn't be much over £1500 again unless very late and vvgc.
