iMovie works a treat with the XL2.
iMovie will alow you to split your audio from your video and so that it will edit much the sam as FCE.
Also, if you go to File/share and hit the quicktime tab, you can choose expert settings. This allows you to export the audio separate( better compression) and also change the aspect ratio to 16:9, change the quality, bit rate( 1 and 2 pass vbr) and will allow you to set the target bit rate.
It also export the chapter markers( if you have added them)
I have pushed iMovie to the limits and it does well.
Any question, dont hesitate

imovie and 16:9
 

i guess the newly-released (yesterday) imovie 5 is supposed to support 16:9, and the price is right!

most of what i need to edit can be done in imovie in an incredibly efficient manner, and the shots that need animation or motion effects can be done in FCE or FCP and then easily imported into imovie. i find this a lot faster than working in either FCE or FCP unless i'm working on a piece which needs a lot of bells and whistles.

Meryem