Big Rainbow, and yes I have grown both,

The gold/red bicolors can be finicky due to weather conditions in any one season, sometimes sweet and lucious and the same variety the next season can be bland and mealy.

But when they;re good, they're very very good.

Carolyn

That is a tough decision to make.

Not knowing either one, if I were to pick one of those I would pick Rainbow, for its nice color. Pineapple is just yellow (is it ?)

I have grown both... I like Big Rainbow better.

Pineapple is advertised and pictured all over the net as a bi-color. I grew it a few yrs back but didn't see the yellow/red size like I do in Mr Stripey. Still it was more productive for me than Big Rainbow but not as large. Hillbilly is another one that comes out as mostly yellow in my experience but the net pics always show lots of red. Maybe I pick them a little too soon. Both are nice plants and set lots of fruit. I only grew BR one time and didn't have any luck with it but will try it again.

Not to hi jack the topic, (Hoping OP to be able to make a decision),;
I have bought several HEIRLOOM tomatoes from store (NO NAME) that looked like MR.STRIPY, BIG RAINBOW and PINEAPPLE. I am growing seedlings from them right now.

I like colorful tomatoes on the juicy side. I can always take care of the flavor by vinegar, lemon juice , salt, pepper and sugar. Rarely I eat plain tomato except cherries.