Historical perspective lends better understanding of the choices...
LTO was originally to come in two flavors:
 - A dual-hub, high-performance 3570-like, cartridge called Accelis;
 - A single-hub high-capacity cartridge called Ultrium.
Accelis did not make it to market because the need was more for capacity
than speed, and Ultrium's performance was deemed "good enough" for
all-around use.

Ultrium remains an affordable, mid-range, open-systems tape technology,
better at streaming than start-stop.  Proprietary Magstar 359x technology
continues to occupy the high end, with superior start-stop characteristics
which make it the best choice for primary storage pools.

Various documentation compares technologies, such as:
 "IBM LTO Ultrium Performance Considerations"
  ftp://ftp.software.ibm.com/software/tivoli/whitepapers/wp-tsm-lto.pdf

>They do look nice, but I still hate the thought of the dataloss, if one cart
>gets damaged or fails.  ooooh.

(chuckle:-)  People were saying the same thing when 3490E allowed us to
put a whole gigabyte onto a tape cartridge.  It's all relative.

   Richard Sims   http://people.bu.edu/rbs