Adderall is a mix of levo-amp and dextro amp at a ratio of 1:4 respectively. The levoamphetamine while good for some people is not the best solution for everyone, and gives many users some of the PNS side effects that are not beneficial at all to the patient.
This is why, Dexedrine would be a better idea, it's the pure dextro isomer of amphetamine, so it has less PNS side effects and more of the good isomer.
For those who still have side effects on Dexedrine, Desoxyn (dextro-methamphetamine) can be considered. In my case, I had side effects with Dexedrine that I wasn't content with so I switched to Desoxyn and have never been happier. There is no RX stimulant with less side effects and definitely not one with it's efficacy. This is my subjective experience, others are happy with Dexedrine, others are fine with Adderall.
Methylphenidate (Ritalin, Concerta, Daytrana, etc) blows and is not a good stimulant IMO, I don't like it's chemical structure or it's lousy effects, I've tried every form of it, they all suck as stimulants but they may be helpful to some people.
Vyvanse IMO was created basically as a less abusable form of Dexedrine, created as a pro-drug to deter use of any ROA other than oral, and is no better than Dexedrine but some people feel it's smoother or released at a more even rate, and some people like that but IMO it's less reliable than Dexedrine.
Desoxyn > Dexedrine > Vyvanse > Adderall for the amphetamines.
As for the modafinil, I think it's important for people to explore non-amphetamine options so all options are brought to the table before an educated decision can be made.