My experience has been that the aluminum wheels provide a better more planted ride than the "cheaper" steel wheels. I've hauled a few different units over the same stretchs of hwy and i can almost tell you from the driver seat which ones are steel and which are aluminum from the handling differences.
1990 Jayco 250 Special
2008 Ram 5500 DRW 6.7, Cummins, Aisin auto
Holland/Binkley 5th wheel, Reese Dual Cam, and more
232,500 kms in 2013
200,000 kms in 2014
160,000 kms in 2015