Hi David

I have used STK-9710 and IBM-3494 libraries within the past 6 years.

The 3494 is by far more robust.

The checkin and checkout procedures are simpler.

The dual gripper is an issue.  In six years I have only seen a problem with
a gripper once.  Therefore I would not consider it from a standby point of
view.  Under extremely rare occasions when you are doing massive amounts of
quick tape mounts and dismounts the second gripper will give you a
performance boost as it will tape a tape to a drive, dismount the tape
already in the drive using the second gripper and insert the new tape.  I
have never noticed any real performance gain by this.

On the down side, you lose 10% of the tape slots in your library.  Both
grippers must have equal access to all slots.  With two grippers the top
gripper can not reach the bottom two rows of slots and the bottom gripper
can not reach the top two rows.  Therefore those rows are covered over.

The drives are the most expensive part of the library.  I can go on and on
about how much I like the 3494 libraries.

I do have one pet peeve however.  With the library doors closed (a must for
the library to be in use) the message screens on the front of your 3590
drives are next to impossible to read.

If you have any further questions about the 3494 I would be happy to help
out.

Jim Taylor
Senior Associate, Technical Services
Enlogix Canada
E-mail: jtaylor AT enlogix DOT com
Office: (416) 496-5264 ext. 286
Cell:   (416)458-6802
Fax:    (416) 496-5245