Backup Technologies

We are a multi-platform data center, migrating to a single enterprise-wide backup solution. Estimate ultimately up to 4 TB. I am not sold on DLT’s especially due to the leader issue. Do any of you have any first hand experience with DLT, 8mm mammouthor (my favorite) AIT’s? If not first hand do have any acquaintances who do and you can put me in touch with them?
Thanks,
Dennis