I'll 2nd round robin. Its simple and fair.
Isotope seems cool but I would guess the usefulness really depends on what you sell, the volume of leads, number of reps, and whether you value tenure or churn through new reps often. For example, their scoring seems to be focused on consumer and home services.
And if you're not rolling out active, parallel training & enablement, as well as monitoring and correcting for the mix of leads, I would worry that you're going to create a secret disadvantaged class of reps who will then be on unfair comp plans.
