Does focalin (dexmethylphenidate) work better or worse or differently than the other add drugs on kids?

Same. As the drs. Said, it's the right half of the methylphenidate molecule & the dose is 1/2 that of ritalin. Focalin (dexmethylphenidate) xr's onset is 30 minutes & it lasts ~ 10 hours. Because it releases 1/2 the dose initially & the other 1/2 4 hours later, some kids get "rebound " symptoms late am if they are " rapid metabolizers"& the the first dose wears off before the 2nd kicks in, requiring increasing the dose.
It is a stimulant. Focalin (dexmethylphenidate) is the active half of methylphenidate (ritalin), so it's major difference is that it takes half as much to have the same effect. It also lasts longer than methylphenidate. Some claim is is "milder, " but that is unproven. Side effects and benefits basically are the same as other stimulants.
Depends on the Child. Unfortunately this depends on the individual, and you cannot with 100% certainty know how one med for adhd will work on one patient until you try it. I have had patients do wonderful with focalin, (dexmethylphenidate) and I have had patients do horrible on it. You just have to try it and watch carefully for the presence of benefits, and the absence of side effects. If Focalin (dexmethylphenidate) doesn't work there are many others.