WOW!! I see from the comments that there will never be a consensus of opinion here!! That is as it should be, but I vote for "indoor" only and my three TUX beauties seem to be very happy with that state of affairs.

It is true that the average outdoor cat lives an average of 2 years. As for indoor kitties, well, with all the advances in veterinary medicine and nourishment, they can live for 20 years or more. It seems like a "no brainer" to me, but I know that many people feel that a cat is not a "real cat" or living a "real cat's" life, if it does not feel the grass under its little padded feet. Those people are definitely entitled to their opinion, but I remain steadfast to my viewpoint which is strictly indoor.

Just my humble opinion from
Deborah in Montreal, proud owner of Prima (almost 16 years), Picasso, (6 years) and Piano (one year)