The Alarm doesn't sound , of course, like the Vintage, which sounds like a big frog before Love... 
The weight of the original '65 is exactly the same than the original '68, so you can feel the light difference.
The shape and the size are identical, as the Vampire effect.. 
The main thing which changes is the movement...
The cal 825 has something the new movement doesn't have: The nice feeling of the umper and its legendary " Dong Dong " when you move the watch, and the physical feeling you have on the wrist when the watch moves, too.
The modern movement allows some nice improvements, like the quick set of the date, by the crown at 2, and the nice Alarm sound, even if the frog in love had its charm.
In temrs of accuracy and reliability, a modern movement is without doubt superior and better.
Thanks for the share, my friend!
Best,
Nicolas.