EDIT - My original calculations did not take into account the shockbolt bow nor the +1 to hit for the judicator prime, both of which will lower the Judicator's scores. I've updated below.
EDIT 2 - I've fixed two errors in the text below pointed out to me by C4st3r. There happens to be a lot of text removed (but luckily, very little of the math). How embarrassing for me.
Judicators v. Vanguard Raptors
Judicators (5) - 2/3 to hit, 2/3 to wound, 1 damage, 4 shots + 5/6 to hit, 2/3 to wound, 1 damage, 3.5 shots = 16/9 + 17.5/9 wounds = 33.5/9 = 67/18
Vanguard Raptors (3) - 4/6 to hit, 2/3 to wound, 2 damage, 3 shots = 8/3 wounds PLUS 1/6 to hit * 2 mortal wounds, 3 shots = 1 MW
Against armour: Judicators have -1 rend, and the VR have -2 rend.
Against 3+ armour, Judicators will do 33.5/18 (=1.86) wounds and VR will do 16/9 + 1 (=2.78)
Against 4+ armour, Judicators will do 134/54 (=2.48) wounds and VR will do 40/18 + 1 (=3.2)
Against 5+ armour, Judicators will do 335/108 (=3.10) wounds and VR will do 8/3 + 1 (=3.67)
Against 6+ armour, Judicators will do 67/18 (=3.72) wounds and VR will do 8/3 + 1 (=3.67)
Unsurprisingly (given their higher rend), VR will consistently do more damage against armoured targets. Against:
3+ armour, they do 1.49 times more damage,
4+ armour, they do 1.29 times more damage,
5+ armour, they do 1.18 times more damage, and
6+/- armour, they do 0.99 times more damage.
They are also 1.25 times more expensive (180 v 160 pts) which means that, in terms of damage output, Vanguard Raptors are a more efficient use of points when facing 3+ and 4+ armour and Judicators are a more efficient use of points when facing 5+ and 6+ armour.
- RESILIENCE - Judicators have 10 wounds instead of VR's 6. So if your squad takes 5 wounds, the Judicators are still going to be pumping out over 75% of their full strength damage and the VR squad will be pumping out only 33% of their full strength damage. If the squad takes 6 wounds, the Judicators are still dishing out approx 65% of their full strength damage and your VRs are wiped out.
- BATTLELINE - Judicators happen to be battleline in any Stormcast army, whereas
you need a Lord Acquilar to make your Vanguard Raptors battleline.Vanguard Raptors are never battleline. This can be a big deal depending on the rest of your army (i.e. you need to fill out battleline slots). SYNERGY - By combining with a +1 to hit bubble, the VRs will do an average of one extra MW per turn (which is pretty awesome). However, they'll do a little less damage through regular wounds (since the Rule of One states that a natural roll of one before modifiers fails). So although the VRs will do an average of 2 MW per shooting phase, they'll do 25% less damage otherwise (because 4/6 to hit becomes 3/6). Note that under these new percentages (set out below), the VR's do 1.29 times more damage to 5+ armour and 1.08 times more damage to 6+ armour. It's still increasing their damage output as follows:
Lord Celestant (on foot) synergy
Conclusion - so are Judicators or Vanguard Raptors better?
Personally, I already have a unit of Judicators so I'm likely to grab a squad of VRs so I can see which work better with my style.