I just watched the RoninFox version (so yes I just watched tWoO back to back). It's pretty good too, but I have to admit I liked the Rifftrax version better. For one thing they did the singing bits better.
I thought it strange how many identical (or with a slight variation) jokes there are in the riffs. Some were just obvious jokes, but some others make me wonder if Rifftrax watched the RoninFox riff before writing their own.