I have been very happy with my SI feedwagon.  I just filled it before dark last night to give the cows on cornstalks something good to eat during this weekends snowstorm and cold weather.   The paint has held up excellent for the last seven years and the trailer is built very stout - it looks like new.  If you feed poor quality feed or feed with dirt in it you can roll the trailer over to empty/clean  it using a loader without any damage.

edit to add: if feeding round bales only, you do not want solid sides as you would for silage or ground hay.