This 4-BR, 4.5-BA stunner on Commonwealth Avenue in prime Back Bay has a lot going for it: 4,250 square feet in a building dating from the Hayes administration; double entry doors with a wrought-iron grill; a sunny, south-facing living room; very high ceilings throughout; an airy chef's kitchen; a marble bath for each bedroom; and four goddamn parking spaces, including two garaged. Yet it's been on the market for nearly a year (give it another few weeks), even after a $150K price-chop right before Thanksgiving. What might be holding it back? According to the listing, it "has the feeling of a private townhouse." Does a feeling justify a $4,625,000 tag? We report, you decide.