Here is what I noticed about the Heroic potion buffs:
1) They are sheer-able.
2) If any of the 6 buffs remain on you, using the potion to give you full buffs again will fail, but will still cost you one charge from the potion. You have to cancel whatever buffs from the 6 that are left in order for the potion to buff you again.
-----signature-----
Shadora, Perc - RR11 inf
If it's in the game, we will shut 'er down... EA