I like a witbier every now and again.
Using raw wheat is best served by getting those starches fully gelled so that the enzymes from the malt can convert them to sugars. A proper "cereal mash" accomplishes this purpose along with starting some minor starch conversion to help things along. An alternative, is to simply cook the (milled) raw wheat until it's fully gelled/softened, and add that to your mash. Another alternative, and what I choose, is to mill your raw wheat to somewhat fine particles and mash it that way without any kind of cereal/cooking step - a step mash is beneficial in this instance to help the raw wheat to better gel and convert at each stage.
Making malted wheat, on the other hand, would require a controlled sprouting of the raw wheat followed by a drying/kilning of the sprouted wheat once the acrospires reached the desired modification level. Again, fairly easy to do but takes some time, effort, and extra equipment to complete. Buying malted wheat is easy and cheap.
Flaked wheat is gelled, raw wheat that has then been dried out again. It's is perfectly suitable for direct mashing without much benefit from step mashing. It's kind of like "easy raw wheat" and provides basically the same character as raw wheat would.
My opinion is that Raw/Flaked wheat is more neutral in flavor, gives a creamier mouthfeel, and a hazier end product; whereas, malted wheat has a slightly more "malty" flavor (subtle), less creamy and less hazy.
I actually prefer a mix of well-milled raw AND malted wheat in my wits. No cereal or precooking - just step mashed.
Hope this helps.