I must say I do not think the speed advantages are worth the credits...
I was not going to get the 3rd rank (310,000), but when i dinged 50 and got my final set of training i accidently bought the licence, so I had to get the Dark V speeder (99,000).
I think the speeder differences dhould be much greater for the price tag, I feel it should go...
Rank 1: 90% faster than walking
Rank 2: 120% faster than walking
Rank 3: 150% faster than walking
Maybe then I won't feel as ripped off.