Blitzkrieg is probably one of the more underused abilities, but can really help in many situations.
Blitzkrieg During Cloak
This could really save your ass at times. Have a sniper blob unsupported and a blob is about to charge their position? No need to retreat. Keep you snipers on cloak, activate Blitzkrieg and your snipers or Stormtroopers move normal speed while cloaked.
Saving your Infantry/Vehicles
You can use this ability to act as a 'Retreat' for your infantry and can be used for vehicles in a way you would do for your PE AC's (overdrive). See a fired-up airborne blob about to charge your stugs? No problem activate Blitz and it will save their lives.
Assaulting
Probably the most obvious, hence the name "Blitzkrieg Assault". You simply hit the button and charge the enemy position with your forces, and your tanks get buffed in fire rate at a cost of accuracy. Great for crushing enemy infantry, like you would with M10s. Also good for your Panzerschreck Grenadiers/Stormtroopers when you decide to quickly charge a tank to take it out whether full or slither of health. And since this ability ignores suppression, it is very useful for taking out MG nests with your Schrecked squads.
