Leo: Panama City today is a very modern city from when we lived there in the 60s, but the country's growth and Panama City specifically, has been phenomenal. The current government has successfully built a light rail subway and elevated train system around the inner city. It's called Metro and there are currently 12 stations using both subway and elevated trains. Search Metro Train, Panama City, Republic Of Panama for excellent videos and plans for expanded growth. Only the first leg of a three phased developed transportation system has been completed. For grins, you can take the PanCanal Railroad from Balboa to Colon for a few dollars. The railroad with vintage passenger cars meanders through the jungles and parallels the Panama Canal from Atlantic to Pacific. Station is in inner city and goes to the Atlantic side.
Also, Miaflores Locks near Panama City is a nice place to get a close look of how the ships are lifted to transit the canal. Really nice with a close observation platform to see the full workings of the once "wonder of the worlds." Hope this helps.
Be careful in Colon if you go and don't stray away from the crowds. I don't think there are any casinos there unless they are connected with an American-based hotel chain.
Have fun in Panama -- it's like being in Paradise.