I have been running a squad of Vanguard veterans since BoLScon and they have been an ace for me. With the Descent of Angels (only scatter 1d6 instead of 2d6 plus you can reroll reserves for jump units) you have a unit that is very reliable at assaulting the turn they arrive via deepstrike due to their Heroic Intervention special rule.
In today's gaming environment one of the tougher armies you will face are Space Wolves. They have access to cheap Long Fang squads they can bubble wrap with Grey Hunters or Thunderwolf cavalry. The Long Fangs will pound you with their missile launchers all game and this is a huge strength for the Space Wolves. Now enter the new Blood Angels codex which has access to the Vanguard veterans (VV). This is a strong assault unit that can reliably charge an enemy unit the same turn you deepstrike. I decided to try them out as a counter to Long Fangs. The VV have turned out to be a great unit to fulfill the role as as an assault sniper. By eliminating one squad of Long Fangs you can put a big clamp on the amount of shooting pouring out from a Space Wolf army. Many SW players simply rely upon their Long Fangs for long ranged shooting so by eliminating one pack you may cut their effective output in half.
A wise and canny SW player may opt to bubble wrap their Long Fangs with a deployment in such a manner that you cannot assault them with your VV but then that will open up other avenues that can be exploited. I always equip the sergeant with a thunderhammer and try to get him into base to base contact with an enemy tank while the rest of my veterans assault an infantry unit using a multi assault. Even if the thunderhammer only glances the tank then at least it won't be able to shoot the next turn. Often you'll catch your opponent offguard with your Vanguard veterans... There's a good chance the enemy will have not moved their tank prior to the charge so then the thunderhammer will automatically hit and with at least three attacks versus rear armor you will probably score at least one penetrating hit.
In my opinion for VV to work well you'll need several jump units so you can apply pressure at different points along the perimeter of your opponent's battle line. This will further help to ensure your VV can maximize their potential for destruction. If you can multi charge more than one enemy unit then you will probably be able to destroy one and keep the other tied up the next turn. This takes a lot of heat off the rest of your army as your opponent must then commit some of his army at eliminating your VV. Some armies such as IG don't really have a good solution for a unit such as VV when they are stuck in assault.
There are some different philosophies currently afoot as how to best equip your VV. I typically run the following unit:
Sergeant: thunderhammer and stormshield
Veteran #1: lightning claw and stormshield
Veteran #2: lightning claw and stormshield
Veteran #3: lightning claw and stormshield
Veteran #4: power sword and infernus pistol
Veteran #5: chainsword and bolt pistol
Sure it is an expensive unit weighing in at over 300 points but they are uber Killy and can soak a lot of punishment due to all those stormshields. Stormshields are one of the most powerful piece of wargear in 5ed due to the 3++ save. In my opinion VV are the optimal unit to equip with stormshields since they will garner lots of attention from your opponent once they arrive. You'll probably destroy the first unit you assault so except to see them torrented the next turn. Remember that with the stormshield you always get a 3+ save. I kit one veteran with an infernus pistol so my VV can tank hunt after the initial attack. Also the veteran with the infernus pistol benefits from +1 attack which helps bump up the kill count. Remember that you can't shoot if you choose to declare Heroic Intervention. The sixth veteran is there simply to soak one wound so I don't lose a more valued veteran.
You can always opt for a cheaper unit by forgoing the use of stormshields. They are still just as strong on the charge and will gain +1 attack if you take power weapons instead of the lightning claws. I think the combination of lightning claw and stormshield is the best option for your veterans as the lightning claw allows you to reroll wounds but does not benefit from the +1 attack unless you take a pair. My VV usually will last through the midgame since they have the stormshields and often kill as many points as they are worth.
One last note on your build for VV - this unit can easily take the place of veteran assault Marines from the prior codex. As such you could opt not to use Heroic Intervention and attach an HQ, Chaplain and/or Sanguinary Priest if you want an uber plus Killy unit. In this mode there is not as much need for the stormshields so you can run a larger unit which equates to more attacks in close combat plus you could toss in another infernus pistol.
Finally a note on the use of Heroic Intervention... Sure there will unfortunately be those times when they mishap but believe me when I say those case will be very rare. I have used mine in over 20 games now, once they mishapped and another time they managed to scatter back out of assault range. It's not something I worry too much about. The average roll on 1d6 is 3-4 so if you place them correctly even if they scatter straight towards an enemy unit they won't mishap. This is another reason why I feel that six is the right number to field. Do the math and you'll see why.
GBF is a long time Blood Angel player and against all odds has found a pretty down and dirty use for the VV's. What do you think? With the cool Blood Angel special rules will we start to see more and more vanguard hitting the tables?