"I would prefer to stay within Intuit since I'm used to it."

ProSeries and ProConnect are totally different under the hood. The only common element is both are owned by Intuit.

And the Tax Planner sucks from what I've heard around here..

This post has a comparison chart, FWIW https://accountants.intuit.com/community/practice-advice/discussion/how-do-you-decide-between-lacert...