Son gave the 'flat bottom V' sharpening a shot a few years ago and didn't adjust to it. Seemed the edges were more fragile too so more could go wrong with them.
For me as a parent the biggest improvement is to switch-out the blades day one of the skates to better quality steel. For $50 a pair the better steel just holds up better and holds an edge longer needing less sharpening. Pays for itself in a couple months time and lasts longer.