Dont worry about an '05 due to it being the first year of a new design. There are some things to be concerned about but they arent exclusive to '05 models.
Timing chain tensioners- The timing chain tensioners can go bad early and get noisy. Some do, some dont. There is a tech bulletin out for the repair of these, but no recall. Supposedly the parts are updated. Some who have had the problem have gotten Nissan to warranty the problem, some havent been so lucky.
Fuel guage sensor- Alot of us are encountering this problem. The in-tank sensor on the sending unit goes bad and screws up the gas guage readings, including the dte (distance to empty). Nissan just announced a recall on these but it doesnt include '05 models... not yet anyway.
Nissan is getting plenty of complaints from '05 owners, so we will see. The part is about 80/90 bucks but the fuel tank has to be dropped to service it. A repair from the dealer will cost you much more.
Transmission cooler leakage- Lately the big concern has been the radiator trans-cooler gettting an internal leak and coolant contaminating the transmission fluid. It is very easy to bypass the internal cooler to prevent this problem. 45 minutes under the car, and free to do, if you do it yourself.
IPDM/ER Module- There is a fuse/ relay panel under the hood that is known to go bad and leave the car dead, randomly. It could die going down the hi-way, or while trying to start in your driveway. The part is about $200 from the dealer. It is easy to replace though, it literally took me about 15 minutes to do it. The replacement is also supposedly updated.
I have an 05 that I bought 3 1/2 years ago. It had 16,000 miles on it when I bought it. I now have almost 110,000 miles on it. The only problems I have had from above are the fuel guage sensor, and the IPDM module. Both have occured since turning 100,000 miles.
My Pathy has been a fun, reliable car. I have made a few mods to it, taken it to the drag strip, been across the country a couple of times in it. Towed a few big loads, hauled people, gear, etc. I am not disappointed in it at all.