I've had the below hayabusa car since 2005 - I dont use it anymore and let my brother use it now - great car (Sand Bullet) - never had gearbox issues (stock 2000 engine) - and only had to replace the sprockets and chains every season or 2...all other issues have been self-inflicted - poor maintenance, my shitty wiring job, jumping it, etc.
That said - If I had to pick one - I'd get the tech 3 - those are awesome cars...great size / look cool, etc. Plus with the hayabusa you are limited on watts from the stator, unless you put on an alternator kit...so things light heated seats, light bars, electric power steering, etc, can be an issue and you have to be mindful on upgrades. Stock stators are ~300 watts IIRC. Just my opinion.
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