Here is what I will be looking at when comparing the homes:
1) major routs and green areas (highways in close proximity but not right by the home; no noise; green and quiet area vs busy street);
2) what is surrounding the subject home: better housing increases the value of the subject home, housing step down from the subject make the subject's value decrease;
3) the land: the size of lots, the quality of lanscape of the subdivision and the surrounding subdivisions;
4) exterior construction materials (brick vs siding) and curb appeal (closely connected with point 3 + parking;
5) older homes pricing is tested by the market and is more correspondent to the market trends. The new construction pricing is based on the builder's estimates and will be tested by the market later. Therefore in most cases buying new construction is more risky in paying "not fair price";
6) floor plans and bigger rooms vs decorative materials: you can always renew the countertops, but you are stuck with the floor plan and the house structures (ducts, fireplaces, ceilings height).
7) be aware of the average prices of granites, SS appliances, carpets, hardwood floors, tiles, so that you would not pay twice as much as necessary buying a brand new home.
All the best!