The new Sicaran Arcus is an awesome looking and quite dangerous tank. It's anti air capabilities are very impressive.
The options of firing 3 different and very specific missiles is very tactically advantageous.
The Arcus Warheads are very good against squadrons of skimmers.
The Skyspear Warheads should see most aircraft falling from the sky after a barrage from these.
The Pyrax Warheads are great against Eldar, Solar Auxilia, Mechanicum and Tau.
The Neutron Flux rounds are very obviously the reason why the Mechanicum do not like this vehicle.