Reckless is way better than intimidate. It gives a huge boost in power to all of its best moves, including, if I'm not mistaken, Close Combat. Staraptor is best used as a suicidal blaster, to knock a huge hole in the enemy team before it dies to recoil damage. It's too frail to make its bulk worth preserving, so Intimidate is honestly kind of pointless when you consider the trade-off in raw power you have to take to use it.
To illustrate my point, with Reckless, Adamant CBRaptor has a chance to 2HKO the physical wall variant of Zapdos after stealth rock damage - and that's with Brave Bird, which is resisted.
252 Atk Choice Band Reckless Staraptor (+Atk) Brave Bird vs 248 HP/228 Def Zapdos (+Def) : 38.9% - 45.95% (2-3 hits to KO)
If you go with Double-Edge, assuming you have Rocks up, you OHKO it.
252 Atk Choice Band Reckless Staraptor (+Atk) Double-Edge vs 248 HP/228 Def Zapdos (+Def) : 77.81% - 91.91% (Guaranteed OHKO)
However, with Intimidate, that becomes somewhat of an uncertainty.
252 Atk Choice Band Staraptor (+Atk) Double-Edge vs 248 HP/228 Def Zapdos (+Def) : 65.01% - 76.76% (18.75% chance to OHKO)
It's the sheer power of Reckless Staraptor that got it banned from UU. Use it.
