In fact just the other day (2500 miles after last oil change) I put the left over pint from the last change in which brought it right up to the fill line. Seems like owners of 2.5s experience similar volume discrepancy albeit with the slightly larger volume of oil that engine uses.
I'm not sure why there is such a discrepancy in oil capacity reported but I'll suggest three possible reasons:
1) Some people may check their oil after the engine has been run but not up to temperature. This will leave a lot of oil clinging to engine surfaces and make it appear to be low.
2) Not waiting long enough to get a meaningful reading.
3) Variations in side/side or front/back leveling of the vehicle.
I always check oil level in one of two ways, either after waiting at least 10 minutes from a fully hot engine or after sitting in a level spot overnight.
The 2.0L engine is spec'ed to take 4.4 quarts after drain/filter change so it will take a little more than 4 quarts to get it to the top of the high mark on the dipstick but, the point is, the oil change kits come with 5 quarts yet you will not need 20 quarts to do 4 oil changes, closer to 16-18. So buy a couple extra and you should be good to go.
Personally, I'm comfortable filling it to just above the middle of the range on the dipstick because my engine doesn't burn a drop of oil - the level 7,000 miles later is right where I put it.