I've gone through several in my '81 Vanagon.
The repair shops I favor recommend them.  (Also
put them in a '90 80 Audi.)

Batteries always last (length of guarantee) +/- (1 day)!

Actually, they last 5 years + N months--to the first
really cold Colorado weather!  That was last December
for my previous battery.  Now headed to winter #2 on
the one I bought then.

I've never had any other troubles with them.

                        Richard A. Jones
                        Boulder, Colorado
                        '81 Vanagon  Mr Bus