When you say you want to sharpen your Agile skills and leadership - are you referring to the PMI-ACP certification?
If yes, then I can share my experience here: I did use the PM Prepcast material and tests to prepare for the PMI-ACP exam (and passed).
Reasons I would recommend it are:
1. Exam questions are very similar to the Prepcast
2. Value for money - there are many, more expensive courses/ exam prep guides our there, but this was very reasonably priced
3. Flexible modes of learning - can listen to the audio podcasts on the go, anywhere.

I need to sharpen my leadership and Agile skills. With my packed schedule, I need the most efficient way to prepare.
Which courses/resources did you use? Were they effective?

Thanks in advance!