U'd build your first depots to block tha back of your minerals cause of reapers and you can use those depots to trap a reaper there also. Really no need to wallin in TvT. Build your first buildings (barracks) close to your command center to avoid wasting gathering time. I recommend making maras from two rax or making a starport pretty early for tank vision in TvT.
i did a wallin cuz i went 1 rax marine only cuz i wanted to get my siege tanks fast. i am not afraid of reapers and i didn't really need the depot there
a few marines will hold off any reaper harass, especially since i was staying in my base
Have yoo ever fased delayed reapers? . You didnt stay in your base when you moved out with your army. One reaper could have killed some of your scvs and kill a marine or two. Then again when you come back to kill the reaper he just runs away cause theres nothing to block it.
No need to really wallin in TvT but it doesnt matter that much. But still every minerals count!
i know tehre is no need but i would be pretty dead if he would push early with M&M. so a wall in here is a good idea.
i saw good people doing it, trust me it is the way to go in this case:P
Yeah hellions are for same use as repers, but they have area dmg and thet brilliant upgrade and cost "less". But then again reapers are a bit more mobile.