We have parked in both. The ecomony lot is a bit further out but only by maybe 5 minutes. The shuttle bus runs very frequently and as with the preferred lot they take you to your car! Last time we fly out of the economy lot as we pulled into a lane the shuttle bus started to follow us down ready to pick us up as soon as we locked the car! They gave us a card with the car location lane and everything.
As for timing, allow at least 20-30 minutes to park, unload, reload and be shuttled to the terminal - it usually takes around 15 minutes but its nice to have some 'wiggle' room.
We don't usually arrive at the airport 2 hours ahead as we don't usually have luggage to check just carry-on but as with the PP I like time to relax and feel like I am in holiday mode so will always allow at least 90 minutes.
The airport is small with not too much to do there so unless you have things to do at home before going, get there earlier, grab a coffee and paper and start relaxing and getting ready for your holiday.