Hi There. I recently checked out smartpacks for my Arabian, Khaiyaann. He's been SO sick lately and ~anything~ that might help him is worth it to me. Anyway, After much research into the supplements that go into the smartpacks, I found out that each supplement can be purchased elsewhere, in bulk, at a cheaper price. As an example: Recovery EQ can be purchased from smartpack, BUT I found t on Amazon for 1/4 the price! The up side to this is that it saves QUITE a bit of money. The down side is that the owner/care giver has to mix and measure different supplements. BUT if you have the time to open smartpacks, you probably have the time to open a few different supplement containers and mix them with feed.
I don't think that individually packaged supplements offer much more freshness than bulk supplements as long as the bulk ones are stored properly in air tight containers. Personally I wouldn't purchase more than 1-3 months supply of bulk supplements though, just to keep it fresh.
That's just my 2 cents! Your mileage may vary!