User blog comment:DoctorAsawa/The Perfect Jungler (Or Somewhere Close)/@comment-71.45.62.87-20121023062939/@comment-71.45.62.87-20121026023758

I think you're a little confused.

Trundle can start boots and potions, people choose Vamp Scepter for even greater sustain and possibly be able to invade and survive.

His jungle, although not the fastest, is nowhere near slow. He has to be the fastest non-AoE jungler and is probably slightly faster than Amumu if I had to compare him to another jungler.

Trundle fell out of favor because he's Trundle and his damage falls off compared to the junglers you mentioned.