The first time I completed LI HM I was in tionese gear. I was the healer. It was freaking awesome because the columi mainhand and rakata chest piece for my class dropped, and I got both.
Now a days I run it in campaign and dread guard for three reasons that I'll list in priority: fun, to help friends, and for the black hole coms. It's one of the fastest to run, second to T5, I think. It also brings back memories of when I really had to struggle to get through it. All the lawl mistakes I made as a noob make me smile.
The rewards are good enough in my opinion BUT I would really like to see the pet drop more often. I have run that flash point 36894834327487923879478128 times and I have NEVER seen it drop. That's a pretty low rate imo.