Mine grow about the same and 70-80 days for both.
Let me go look at my plants- I'll be back.
I'm back, Both are the same.
Both were seeded at the same time.
Super Beefsteak and Super Sweet 100's are exactly the same hight.
If a disease doesn't kill them and a bug doesn't eat them there may be something left for you.
Zone 47 Sector C