4:6 gears

a friend told me that tweaking with the transmission would result in
a definitely more enjoyable performance out of my beetle. he
mentioned words like closed gears, 1,2 & 3 modifications while
leaving the 4th gear stock and 4:6 gears. my questions are:

1. is it really worth it? is it a lot more fun?
2. if so, why not invest on trannies instead of engine modifications
then?
3. if i do go for it, would i sacrifice freeway performance? is
there a way to increase take-off power and yet have enough power on
long straights?
4. is it high maintenance? is there danger of the car not being
reliable?

my '67 is a daily driber but i want to be able to shut them hondas up
when they give you that 'its an old car not worth driving' look when
they pull up beside you on a red light.
tnx! (again)