I don't have the 510-T starter kit, but, based on the description and comments...
Pros:
Smaller, lighter more streamlined. Closer to a real cigarette in length and width.
Auto option - You don't need to press a button to get vapor, just puff like you would a cigarette.
Cons:
Shorter battery life
Auto
batteries are very sensitive - may be triggered by vibration (sound or light impact).
They have a link about the 510 T starter kit
here.
I really really really love my eGo-T. Yes, it's more expensive but the battery life is worth it. It's more substantial in length/weight so it
doesn't feel like a cigarette (major plus for me, actually. I did the old 510s and the KR808D batteries a few years back - so similar in feel to a cigarette that it was incredibly easy to reach for an analog when the battery died (often) and I didn't have backup. Enough that I dropped the
vaping for 2 years until introduced to the eGo.)