Okay, I didnt make the video, so I dont feel guilty for the easy listening. I would have gone with Johnny Cash if I was gonna do any country
Erm, I don't do videos, I would probably phail at making one

so here is some snaps of my best spots for Engi.
May Edit: Bold Text is amended information
First up is Stage 1 Teleporters:
This spot, above all others. Because it is outside of the effective killzone of any pesky scout or spy, and those are whom you have to worry about knocking out your teleporters 99% of the time. If a Demo or Soldier gets back there, you have more problems
On Defense this is a great Teleporter to plant. Very few people (aside from Fearless, who is a MEAN SPY who seems to ALWAYS look there... <_< ) look here, and it will often stay up long after the first point has been taken. Great to leave it on level 1 (so its quieter) and let spies and scouts hop through it to disrupt the offense.
When the first point is lost this is my favorite spot to fall back to. A level 3 will almost always take the offense by surprise - I've taken out whole waves of 8 and 9 before. They all have tunnel-vision, trying to Rush the 2nd point. It wont last very long, its just an ambush spot, but great for stopping those rushes.
This spot above all others, tbh. Almost nobody on offense thinks to look here. In one round I saw 2, 3, 4 ubers charge right out of the caves (2 of them were heavies, shooting right beneath the darn thing) and they just never seem to realize its there until they start bleeding out on the floor. Very durable, almost never goes down.
This spot has since been covered up by a sandy blob of Valve's jealous rage toward clever engineers.
Awesome dispenser spot. Heavies do great when they sit here and spam bullets and things. The other side of the stairs is ok too, but gets shot up more.
Where I'm standing here is a fair SG spot. Guards the tunnel a bit, and you can climb your gun to get back on the ledge, so that you have a good place to tuck away a dispenser.
Just note that the broken wall of bricks to the right is now removed. Not a big cosmetic change. probably makes it a slightly better spot. I dunno yet.
Good spot to use if Red Team is pushing you back before you can rally for a push. Set up dispenser first - no metal for 2 miles.
Stage 2, on Defense, this a nice gun to put up, because Blu rarely thinks to check there. A good Pyro can flank it without support - but thats true of any gun you put right behind the edge of any corner.
This spot is no longer viable due to modifications to map layout
Across the bridge on defense, this spots pretty vital to holding them off for a few extra minutes. Dont stick the gun out farther than you have to. Here, I just want to defend it from anyone crossing the bridge, without exposing it to too much fire. The top priority here is keeping this teleporter up.
This ones good enough to use to defend the first point also, and good for the 2nd point too. Dispenser is mainly for friendly troops to use. It doesnt fall down as often as you might think, unless the enemy is well organised.
You saw this in the video. Once you get up here, you've pretty much won.
Has been removed due to map changes.
Yep, Evil Sentry can see ALL.
not any more...
See the Teleporter? About the only thing that can take this down is a Demo or a lucky Sniper. If the Teleporter is left up, the Defenders will just rebuild the Evil Sentry.
sigh. not anymore
THATS what I'm talking about.
those were the days....but you can see why they took it away. Also, the sentry in the top right of this image is more vulnerable thanks to a new opening in the fence.
Side note, Stickies tucked in the corner, nobody ever checks for these.
This hiding spot for stickies has since been removed. Cover around the CP has been changed up a bit. Though there is a pair of crates on the opposite corner that can help you achieve a similar effect.
3rd stage, this is a good place for a cap-1 teleporter exit.
On defense, a sentry behind the hole is best at killing people below, but is vulnerable to long range attacks from the left. Some people prefer the other side, where its protected by the wall of bricks, but its more open to counter-attacks from below.
The stairs are now permanently open up in the top right of this image: meaning its now terribly easy for a soldier or sniper to pick off this gun.
Good Ambush Sentry.
wall removed, may be a better spot. Predictably low survivability however.
Good for defending the point, and protected from fire by the obelisks.
This is my favorite spot. Gun defends from the flankers, and the dispenser supports our friendlies. I might have nudged the gun a little to the left though - pyros and demos love to edge this one.
This is good if you have a buddy. Acts as a great firebase for friendly troops, its sorta hard to flank as well. Guards the point well. Blu has to stick their necks out from the tunnels to get shots off at it.
note in the far top right of the image, that wall has been replaced with crates. looks better but provides much poorer cover.
As Red, this is a fantastic Ambush spot. If you can get a level 3 up Blu will need to spend an uber to bring it down, or good teamwork. As Blu, its vital to success to put a teleporter here, and defend it with a likewise sentry gun.
Good Ambush spot for Red, but cant see into the cave, or outrange any soldier that wants to rocket jump up from the giant hole. so it wont last terribly long.
I'm sure I left out some other great spots but feel free to add.
I did leave out a spot or two and I will amend that...