Would I have that option even if it is a replacement computer? And I was thinking about getting a Toshiba, because the last one I had has lasted 6+ years.
My 2013 Air works fine. Since day one, including every update up to 10.9.2..
The only computer I've ever had fail on me was my Toshiba. Hard drive died after ~2 years.
What we think should mean very little to you. Our experience is not yours. If you think a Toshiba will work for you, get one. If you want to keep OS X and think switching to a MBP will be some kind of good luck charm for you, get one.
I wouldn't go back to a Toshiba if it was given to me. Yours lasted 6 years and you're considering another one. See how this could go on all day?