One common question buyers of the Tamagoyaki pan might have is with regards to the choice of copper vs cast iron. There are some differences between these 2 materials so it is better to know which is more suited for you. If I missed out on any of the specific details, please feel free to leave a comment.
#1: Maintenance needed
For those of you who like their pans to be shiny and nice, a copper Tamagoyaki pan requires much more mainteanance work. In particular, you will need to tarnish it to bring back the shine after considerable usage. Cast iron, on the other hand, needs only a simple wipe before it is good as new. Of course, if you just want to use it, not to look at it, just this is not an important difference.
To clean a copper Tamago pan, using the copper brush might not work. My trick is to use some ketchup on the pan surface and leave it for a good 10 minutes. The acid in the ketchup will remove the oil and restores the shine. This works very well for me as it is the easy way I know to keep a copper pan looking shiny and new.
#2: Heat transfer
Copper conducts heat pretty well so a copper based Tamago is quicker to heat up relative to cast iron. If you are the type that wants to hurry, hurry, hurry then copper might be a better choice.
#3: Heat distribution
Related to the above is the point on heat distribution. While a copper pan heats up faster, the heat is not even distributed. A cast iron pan typically can distribute the heat evenly because it is thick and avoid you the trouble of having to move the pan. This is double edge sword. While a copper pan requires more attention and movement, it does give you better control as you need to constantly adjust the pan around. Depending on how good a cook you are, this can be either a good or bad thing.
Finally, the cost issue. A copper based pan is cheaper than the cast iron version that I saw selling on Amazon. On average, the difference between the two materials is around USD30-40. This might be a big difference to some but for those on a budget, it can mean a lot. My advice is to choose the one that best suits your cooking style rather than the price. For example, if you are not comfortable with moving the pan around to distribute the heat, there is no point in buying the copper pan even though it might be a bit cheaper. You will simply not use it enough times to justice buying this appliance.
Both copper and cast iron have their good and bad points. Hopefully, this article has shed some light on their differences for you to make a better call on which is more suited for you.