The verdict
If you are an early-stage SaaS on Stripe, Paddle or Chargebee and want to launch quickly, pick Tolt. It does one job for one kind of company, and the portal on your own domain is a good touch.
If you use Recurly or Braintree, or you want lifetime recurring and tiered commissions with clawback rules and tax forms handled, pick FirstPromoter.
The two are close enough that I leave the winner open. Compare them on your billing tool, your payout method and how each plan scales with affiliate revenue. In both, a programme that works will move you up a tier.