I have the S3 Frontier and OG Watch Active so my opinions aren't based on usage of either you mentioned, but their predecessors. The Watch Active 2 looks a little more elegant and classy, whereas the Galaxy Watch has a more masculine look to me. The Active excels at fitness whereas for me at least the Watch works better as a smart watch. The Active 2 has a smaller overall footprint with the same size display as the GW (for the 44mm WA2 and 46mm GW) so if you have smaller wrists you could get a bigger screen with the WA2 without it overtaking your wrist. They have the same processor, storage, water resistance, and RAM, so performance should be fairly similar. One thing to remember is the WA2 has bluetooth 5, whereas the GW has 4.2 so you'll most likely get better BT performance from the WA2. On the other hand, the GW has a bigger battery, so you may get a little more battery life out of the GW.