The disadvantage: Cost. People who hate Colts.
The advantage: Probably the most accurate gun you will ever have. My 6" is the most accurate I've ever had. Many years ago, a truly great pistol shooter, (who's name I stupidly can't remember just now, but who was known as "The human Machine Rest") test fired my Python at Camp Peary. It grouped one ragged hole at 50 yards. He turned to me and said, "Par for a Python, God I love'em". Several years later he went on a sponsered hunt on a Texas game ranch for a gun magazine. He got his deer at 100 yards with a 4 inch Python. Viturally ever gun test conducted on a Python gets simular results. Yes, you will be told all about Pythons that won't shoot. I've never seen one, and I've seen many Pythons over the years.
A true classic design which every revolver maker in the world has basicly copied.
Considered the true Rolls Royce of guns, probably the finest production revolver ever made. HIGH quality. (Yes there have been spotty production problems, but on the whole less than any other guns, which ALSO have production problems).
An incredibly smooth, fine trigger pull, (different from other guns, but great).
The cachet of owning a legend.
If Colt brings it back (fairly certain) 6" barrels and blue finishes are more 'traditional'. But in my oppinion, the bright stainless looks better, since I doubt Colt can match the old "Royal Blue" from years past.
If you can, a better option may be to buy an older Colt. Many are being advertised on
http://www.gunauction.com, and
http://www.gunsamerica.com. GunsAmerica is a straight purchase, not auction, so you may like to make a buy outright.
I own or have owned 5 Python's and never regreted any. All were top of the line.