RE: Katana ST
^^^
What he said.
Something to be aware of: The XXXNT has a reputation for being less durable and more suited to competive racing. If your son is young you may want to keep that in mind.
You WILL break things, no matter what truck you get though. For this reason, it is good to have a look at your local hobby store to see what trucks they carry a good selection of replacement parts for. The Evader has a 1-year guarantee on plastic parts, but that won't get you up and running the next day if your lhs doesn't carry a replacement for you.