The feeding therapist in me ALWAYS prefers high quality feeds over higher quantity feeds. I believe firmly in listening to the patient's cues and pushing them just to the point of success and teetering on the edge of what they tolerate to encourage the next step in their development. However, we cannot underestimate the need for appropriate calories and nutrition.
The truth is, what started the picky eating may not be the factor that is keeping it going. The longer the issue has persisted, the harder it can be to figure out what caused it. And to make matters worse, the longer it has persisted, the more factors that may be keeping it going.