1. How old is your son and do you know this is something he would get into? Consider their 1/43rd stuff if he is younger than 12 or so. It's "less serious" and you can buy extra track sections and have a "longer" circuit in a smaller space.
2. Are you thinking of a permanent track on a table... or at least mounted on plywood, perhaps that you can mount to the wall with hinges on one side and swing up and out of the way when not in use... or are you planning to go rug racing, and take it apart and put it away periodically? If you're thinking of mounting it on a board, and your son is older and you're pretty sure he is going to be into it, perhaps with the two of you racing each other a good bit, then you might want to consider digital at this point because it would be easier to start digital than go to it later.
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