what lozz says,
there is a sound that ampeg cabs have for me its a mid heavy sound, however after playing thru both the 810 and 610 hlf cabs they both have very different quality's, the 810 is alot tighter and more punchy to my ears, but the 610 has a awesome thump in the lows due to being ported instead of sealed like the 810.
for me it was a bit much as i like to use octaves, and alot of gain which made this easily go a bit muddy where as with the more mid focused 810 it was alot easier to control the bottom end, which is why i now use an 810, all be it an ashdown (which can i add is very nice)
def worth checking out the cabs yourself before dropping alot of cash on a heritage cab.
andy