I think you might be adding fat more than you're trimming.

You're talking about moving away from one platform into another platform, plus WordPress, plus integration, plus migration costs, plus training, plus any issues infusionsoft might have minus any issues hubspot has.

Now maybe that's worth it for the design flexibility, but clearly you're adding fat and costs and that means there must be a corresponding increase in returns.

tl;dr: don't underestimate transition costs.