We're approaching this from two different angles.
"If you're talking about currently used technology, you're exactly right. However, something like the 'Myamar' artificial muscles would be significantly easier to maintain in the field..."
"But you also ignore the possibility of direct-fire energy weapons like a particle beam or laser-based gun."
You're assuming technological advances that haven't proven practical / possible yet. I'm assuming current state of the art on both sides. If you're going to assume psuedo-muscles and particle weapons, I can counter with David Drake's tanks equipped with nuclear-driven air cushion drive and plasma guns.
Ask those soldiers on 'Rat Patrol' if they wouldn't rather have something more heavily armored. Ask that gunship crew if they wouldn't rather have something that hauled butt when an enemy fighter pops up. Both are work-arounds until something better came a long - MRAPs and A-10s.
Incidentally, I was an FDO in a 203mm battery for a few years, and had the chance to observe those direct firing. A glancing blow fro that 200lb bullet would probably kill anything on the ground battlefield but with a reload time of almost 45 seconds, you better hit your target with your first shot. Otherwise you've just p!$$ed them off!
