Growing Tomatoes - store bought grow bags or greener self-filled reusable ones?

Look at those tomatoes.  They're all different colours, shapes, sizes and flavours and THAT is why I grow heritage.

In previous years I got my tomato plants from my father in law, but this year I decided to grow my own from seed and compare two different growing methods - using a pre-filled grow bag, and using a self-filled reusable grow bag.  You will see the pre-filled ones in the front in the picture below, and the reusable ones behind them.

I put our own compost in the reusable bags, along with various fertilizers.  The theory was that I would grow the same plants in the back (reusable) and front (pre-filled) and compare their progress.  On the other side of the greenhouse I planted (in reusable bags) my father in law's choice of tomatoes.

From the start, the plants in the reusable bags took off.  The soil was deeper so they got better root growth and didn't dry out as quickly.  Over time, though, the pre-filled plants caught up. 

In terms of yield, this is where my experiment fell down.  I couldn't be bothered to weigh out the yields of each method, though I think from eyeing it the pre-filled bags produced more tomatoes.  This could also quite possibly have been down to the fact that they got more TLC due to being easier to access than the reusable row in the back.

*note to self, don't plant two rows of tomato plants

What is MOST interesting is that my father in law's plants didn't produce nearly as much as my heritage plants.  If you go back to the picture at the top of this image you will see quite a few Black Russians (the ones with a bit of green on them), a couple of Brandywine, and some Tigerella.  There may be a few of the FIL's hybrid tomatoes there, but not many.

So, while the jury's still out on which grow bag method to use, I know I'll definitely be sticking to heritage tomatoes in the future.