I would look at Xactly Incent when commissions are an audit and finance problem as much as a sales operations one. The built-in Commission Expense Accounting for ASC 606, dispute logging and audit trails are what a public company controller asks for, and they are part of the product rather than a bolt-on.
The second reason is breadth around the commission calculation. Territory and quota planning (Plan, with AlignStar mapping), comp plan modeling (Design) and Forecast share data with Incent. A revenue operations team that wants territories, quotas and payouts from one vendor has fewer choices than it might think.
The tradeoff is weight. Incent is an enterprise system with enterprise implementation. A 60-rep SaaS company with two plans will often find CaptivateIQ faster to configure, and a company whose real problem is annual merit increases should not be here at all; that is Pequity or Lattice Compensation.
Xactly also publishes outcome figures from its customer base, including 99.8% on-time payment accuracy and a 90% average reduction in overpayments. Treat these as vendor claims and ask for a reference customer with a plan structure like yours, because overpayment savings depend heavily on how error-prone the current spreadsheet process is.