I have done both and I personally prefer a juice fast exactly because of the soreness and the very little variety in the MC. I have made a compromise and do half and half. I think the effects of both fasts are fairly similar, though my problem is that I can't handle greens or raw veggies without feeling really sick plus I have known intolerances to various veggies, so I do mainly fruit juices. Cooked veggies (during a regular diet) are okay, as long as I avoid those I have an intolerance toward.