As a former soldier, I, for one, would rather go into a potentially dangerous situation with body armor despite its weight than going with out because of the comfort-ability issue, I would rather live.
That is the one thing that generally bugged me was the lack of personal protection in the Trek Universe. I understand about not taking a security team to a diplomatic mission, but any mission where there is a big unknown, such as a brand-new planet, I would take the cumbersome gear.
Granted all the gear will be nullified by a writer, but at least have allusions to it or show a redshirt using them. As for the Klingons' armor, it may have started out as armor, but they are just uniforms.
I always kinda of thought as the Argo as a low-profile for low-tech worlds and there are various different level tech vehicles for each mission profile.
My position stands. They had phaser proof barrels within Starfleet cargo bays. With that, they could've made the equivalent of futuristic Interceptor armor or Dragon Skin armor. The sheer amount of lives it would've saved would be tremendous. Damn you writers and gleefully killing random Red / Yellow shirts.