The verdict
For most small B2B teams starting a programme, I'd pick Tapfiliate. It is quicker to get live, the portal carries your brand, and the commission types cover most SaaS and e-commerce models.
If you want a structured programme with multi-tier commissions, a network with several merchants, or a very broad set of shop and gateway integrations, pick Post Affiliate Pro.
Both have limits to check. Tapfiliate caps clicks and conversions on the entry plan, and its trial is short. Post Affiliate Pro tracking requests rise sharply with each plan, and its trial is 30 days without a card.