The verdict
If your main worry is that reps send the wrong terms or prices, I'd pick Proposify. Approved content and CRM data in the document are aimed at that problem.
If your main worry is that the proposal looks dull or the buyer needs several steps to say yes, I'd pick Qwilr. HubSpot, Zoho CRM and Pipedrive are covered on every plan.
Both need plan homework. Proposify has send limits per plan and per-user pricing. Qwilr's Growth and Scale plans are annual with minimum seat counts, and API access uses credits. Neither is a clear winner for everyone, so build the same real proposal in both.