Today, I'm going to compare these three units and highlight the good and bad of each one.
Vanguard Vets for Blood Angels are simply better than their C:SM counterparts. Not only are they cheaper, but they have Descent of Angels ontop of Heroic Intervention. Vanguard Veterans can reliably come in at the right place and the right time to assault anything in the game. They can take special pistols, carry power weapons and use meltabombs against those stationary artillery units. The best thing about these guys is their ability to come down and turn the tide of battle instantly. If you're stuck in combat with a squad that's wearing you down or if you're getting bombarded from afar from some artillery vehicle, Vanguard Veterans can save the day.
For these guys, I prefer a cheap and effective layout:
5x Vanguard Veterans (3x PW, 2x MB) = 205
Keep in mind that the squad leader already comes with a power weapon so you're only paying for 2 more. For these guys, a Power Fist is another strong investment because of the 2 base attacks, but I prefer Power Weapons and Meltabombs instead. The reason why is because they're supposed to act as a counter-charge element that can free up tarpits (near a FC/FNP bubble) or destroy non-moving vehicles. This is why my cheap squad has 3 guys with power weapons. The rest of your army should have fists already so I'm not really worried lack of S8 on these guys.
The big downside about VV is that they compete for the Fast Attack slot on the FOC. I mean, if you look at it from a min-max perspective, which one would you rather take: 5 models that die like normal Marines that costs 165 points base, or a AV13 Fast Scouting Tank with TLAC and HBs for 145? The choice is quite obvious here.
Next, we have Sanguinary Guard. They come with 5 guys, 2+ armor saves and S4 AP4 Assault 2 wrist-mounted Bolters at 12" range. The big thing to note is that every single one of these guys come with master-crafted two-handed power swords and 2 attacks each. In the presence of our FC/FNP bubbles, these guys just dominate MEQ.
To take advantage of this, I personally like to go with this layout:
5x Sanguinary Guard (Chapter Banner) = 230
Yes, they can carry a Chapter Banner with them; thus increasing all of their attacks by +1 among other things. This means that on the charge, they can put out 20 MC power weapon attacks. If a FC bubble is anywhere near you, whatever you charge will normally die. Keep in mind that Sanguinary Guard can also carry special pistols and take meltabombs as well.. but I think their true potential lies in the fact that they can slay most foes in close combat. Since all their weapons are master-crafted, you get 5 re-rolls for misses so you don't really need a Chaplain. Another good thing about these guys is that if you take Dante as your HQ, these guys become scoring. With FNP nearby, it's almost impossible to kill these guys with anything short of AP2 weapons.
So what are the downsides to these guys? They're really expensive in terms of PPM (points per model). They cost the same as Terminators but they don't have invulnerable saves. The 2+ AS is nice and the fact that they can fly is great, but if they get shot by plasma or melta they're going to go down. At 40 points per model, you're going to hate yourself. In a way, they function as Vanguard Veterans but without Heroic Intervention.
Last but not least, we have Honor Guard. The great thing about these guys is that you can customize them to death. Actually, the greatest thing about these guys is that they come with a Sanguinary Priest that can't be picked out in combat. He's part of the squad, not an IC so he's really safe compared to the Elite versions. HG are also pretty flexible in which you can take them in a Rhino or with Jump Packs. Sure, you can take VV without JP, but why would you? Why not take advantage of their true purpose and one of their Special Rules? Anyways, HG can't HI or do anything especially cool unlike the VV or SG, but they can be customized to the needs of your army. You can take a squad with Meltaguns, Plasma Guns or full Power Weapons. This basically means you can customize your Honor Guard to be anti-tank, anti-heavy infantry or a dedicated CC unit. Not only do they provide that valuable 6" FC/FNP bubble from an untargetable priest, but they can be specialized units customized to your army's needs. Once you take any HQ, they are available at 115 points base and takes up no slot on the FOC. The fact that they don't take up any slots means you can take them in any army. This is great. Once you start piling on the upgrades, their price will go up to what the VV and SG are.
An example of such a unit is:
5x Honor Guard (JP, 2x PW, 2x Meltaguns) = 215
Here you have a unit that provides a 6" bubble of awesome to the rest of your army as well as providing reliable anti-tank firepower. If you wanted to, you can take Plasma Guns and make every infantry or MC on the field think twice before getting close to you. Plasma Guns are actually pretty good on a unit with a 3+ armor save and FNP. Death Guard players would be jealous of such a unit. Another cool thing about Honor Guard you can take them without packs, stick them in a Razorback and ship them off to battle with your strongest melee HQ. The unit is not too expensive and you have the option to take a Chapter Banner as well; further increasing the effectiveness of your HG and the IC attached to them.
The only real bad thing about HG is that in JP form, they're basically less armored SG. AP3 weapons pose a threat to them (especially krak missiles) and they don't have the neat little features that make them really feared. Honor Guard can't really play mindgames in the same way VV and SG can. They're extremely effective and flexible, but their cost can go up fairly high depending on what you give them.
So there you have it folks. The book comes out in less than a week and BA players have some difficult decisions to make. Do you take the Turning Tide VV or the incredibly dangerous Sanguinary Guard? What about the flexible capabilities of the Honor Guard in Jump Packs or riding in a Razorback? It's to no surprise that this is one of the most frequently asked questions in the tacticas of Warseer and B&C. I say they're all pretty good, with HG slightly ahead of the others most of the time because of its flexibility. In the end, it's really up to each individual player to bring out their true potential.