Name: Advanced Guard Tower
Side: GDI
COST: $2400
ERA: Tiberian Dawn
Base Asset: Black_Drakon
The Advanced guard tower is the tier 3 replacement defence for GDI. It replaces the Sonic tower, an interesting but flawed defence (it is like it was designed for base crawl and MCV move strategies, it is overwhelmingly more effective attacking an enemy in their base vs being used has a perimeter base defence). It is a completely different style of base defence, so comparisons will not be necessary.
The Advanced guard tower is a pleasantly average base defence. It is good (not excellent) vs all target types, air or ground, vehicles or infantry.
Dealing with an enemy Orca
The Scrin Storm column is the king of anti-air, the Nod Obelisk is the best anti-vehicle. The Advanced guard tower is better at dealing with infantry squads then the other sides tier 3 defences, but maintains being effective against other target types (both the Obelisk and Storm column are mediocre vs infantry and the Obelisk cannot target air by default).
This attack is too small to be an issue
It is very safe as an actual base defence, and vs small attack groups you can mostly leave it to do its job (obviously repair when necessary). The Advanced Guard tower never really misses anything, it just remorselessly pounds away at enemy targets.
The Advanced guard tower actually does the least amount of damage vs the other tier 3 base defences, but it has a slightly faster rate of fire to make up for that.
Whilst there might be a tendency to allow the Advanced guard tower to do everything, you should be careful. Against aircraft for example, while the AGT is about as strong as the GDI component SAM, because of the cost of the AGT, the SAM is obviously a lot more cost effective vs aerial units (you can purchase 4 SAMs for the price of an AGT). To stop the heavier aircraft, for example the Orca bomber, the cost of the AGTs necessary to cleanly take them out would be prohibitive.
Definitely not cost effective vs the heavier aerial units
It is a similar story against infantry, the AGT will only ever deal with small numbers of infantry. Against much larger numbers (which can often happen in the C&C3 world) the AGT will require anti-infantry back up, and once again, the 4 Vulcan towers that you can purchase for the cost of one AGT will be much much better at dealing with infantry.
This AGT is being overrun by infantry, a Vulcan tower would greatly help here!
A much more effective combination!
So as you can see you are paying a cost for having a 'jack-of-all-trades' type base defence.
Negatives
Just like the basic Obelisk, the basic AGT cannot detect stealth. vs Nod this is clearly something you will have to watch out for (although you might also have to watch out for GDI snipers spotting for Juggernauts), a Stealth tank will be able to pass right by an AGT, so have some form of detection to help if necessary.
It also has issues dealing with the most heavily armoured, heavy damage dealing vehicles (such as the Disruptor, Tiberium enhanced Tripod, Sonic grenade upgraded Mammoths, etc). It will only really weaken them, it is relatively simple for those heavy vehicles to bust through an AGT guarded perimeter.
The Disruptor is merciless!, use units (eg Orcas) to assist the AGT in dealing with it
Also the AGT has a dead zone (a minimum weapon range), which means that if an enemy unit can get right next to an AGT, it will not be able to fire at them! Obviously if you are facing an opponent who is using AGTs then use this information to your advantage (assuming there is some issue with using artillery).
Advanced targeting systems
This is a global upgrade which greatly increases the range and rate of fire of all AGTs (by an additional 40%).
Check for the side dish, it means that the AGT you're facing is upgraded, so be careful!
It also adds stealth detection ('full' range detection 400 as opposed to the half range detection that the tier 1 defences often have), and finally adds significant shroud clearance.
So basically everything it did before, but much better!
A solitary upgraded AGT will deter weak minded Nod players from attempting to ambush an expansion Tiberium field with Stealth tanks, because of how easily the AGT detects and deals with them.
The AGT will deal with larger groups more efficiently, and will even be effective vs the large heavily armoured vehicles that it would have had issues with before the upgrade.
It becomes the safest base defence that actually does what you'd expect, effectively defend your base without you having to constantly micromanage it.