Mystic Adept, has spells, can Summon Spirits, has powers.
Mage, has spells, can Summon Spirits, has powers (Sustaining Foci / Quickened Spells).
Physical Adept, has spells (Adept Spell power), has powers. No Spirits.
Assortment of differences of Astral Perception, Astral Projection, Magic Sense, or similar.
Summoning is really the big mechanical difference between Physical Adepts and Mages (Mystic Adepts). There isn't a difference in Shadow Amp cost for Increased Reflexes power or sustaining foci or quicken spell. Story wise and Narrative differences for sure, but identical mechanically.
And Summoning has it's own separate cost (Needs a Skill).
Thematically, there are huge differences. But Mechanically, Increased Reflexes Amp is Increased Reflexes Amp.
Mage>Mystic Adept (Mage without Astral Projection) > Adept (Mystic Adept without Summoning).
Also keep in mind Deepweed is a thing, either as gear or an Amp. I suspect GM Mileage may vary on that.