I really like the warthogs but spectres look pretty kool
I prefer Spectres, they are a bit easier to drive and are relativly fast
specters are fast, but everyone onboard is extremely open to fire, and plus i am the master at driving warthogs so id have to go with the hog
Maybe you can judge to the pros and cons to both of them which I will post now!!
Warthog
Pros:
Riders are more protected
Can drift
Chainguns are particulary effective against anything but tanks
Cons:
Hard to drive
Can be quite slow at times
Specer
Pros:
Fast
Carry more people
Can do a burst of speed (I think)
Cons:
Riders prone to gunfire
Easier to see (because it's purple )
As you see they are pretty much balanced but, really it depends on what you like. It's either speed or strength, what will you chose?!