The 420 is a decent blower. It handles most situations well. If you have large expanses of land or expect to encounter tougher things to move like wet leaves, bushes or other things that could trap what you are trying to blow, pine needles, etc. I'd recommend the BR600. The 420 is no slouch but there is a noticeable difference between the two.

You got a lot of leaves, get the biggest blower. take a look at the Shindaiwa EB802. This is a 79cc big blower. Not very expensive, been out 2 years and get some good feedback.