I just posted my AEM Intakes in the classified with some quick thoughts/comparisons to the Z1 Long Tubes.
Like New AEM Intakes
Summary:
AEMs are way better looking and have gains across the entire RPM range.
Z1s feel stronger above 5500 RPMs but felt like a downgrade in the rest of the RPM range. I'm still sticking with the Z1s as I add the Z1 Ported Plenum and Tune in the next couple of weeks and feel the gains will be more substantial and evident at that point.
If you are looking to keep it simple, I would recommend the AEMs over the Z1s.