Slitherine

Is carbine armed horse worth taking instead of its Impact Pistol siblings?

It all depends on which army. Sometimes you don't have the option for impact pistol, then the option is shooty reiters with pistol -pistol or carbine - pistol. The carbine has the advantage of longer range, but can't caracole to fire in 3 ranks.
I am delirious with the rainbow of options in the Renaissance period!

Carbine-armed armoured Parliamentarian horse is the BEST! Just ask deadtorius how much his Royalist cavaliers like them.

While you usually only get one shot off before impact, it takes the initiative away from the cavaliers in that they HAVE to charge once within carbine range. Protected Shot will offset some of the negative impact. And a single hit can be the cause of death!

In my whole two games played so far, I'd say that they are pretty good. I've used LH armed with carbine and Cavalry armed with carbine and pistol, and in both games they auto-broken enemy cavalry units through getting only 1 hit each but that lead to failed death rolls.

I think Blathergut has it right when he says that they can't be ignored, in my games they've caused the enemy to change target to the carbine armed Horse which allowed my own Determined Horse to pick their moment.

I tend to use them as cheap support for decent frontline troops, either impact horse or pistol curassier. They are fine & cheap enough at 36 pts for a bg to do that.