I ended up playing last night anyway, working on some Engineer tactics.
I find a lot of success placing sentry guns so that they cover not the control point, but the area left or right of the control point. A sentry gun that covers the point directly is a prime target for the enemy, who'll do all they can to uber it down--and often the rest of your team--before capturing. However, a sentry to the side of the point--while unable to fire on a capping team--scores big time assists when your team rushes in to shuffle them off the point and into the bullets of your sentry. And if a capping team ubers, their capture progress halts, and they need to move off the point to attack your sentry gun.
Works well on KOTH Yukon, and several of the points of Steel, which each have teensy crevices the enemy is safe from your sentry in, but cornered dogs for your team.
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Sometimes I speak in walls of text. I will never be offended if you tear it down.
I believe I am cousin.