Want to invest in a new griddle (family down to three since two kids are in college, so doesn't have to be huge). Assuming my best two options is a cast iron griddle for the gas stove-top that covers two burners. Other option would be a propane griddle (would of course have to be outside). Can anyone comment on your experience with the pro's and con's of both? I'm going to assume an electrical griddle isn't even in the conversation. But I could be wrong...