I did not vote, cause I am indifferent. Both setups have their place. With a basic twin turbo set up is usually for middle of the line performance. The twin similar sized turbos will spool at a decent rpm and make good top end power.
If you are going for flat out hole shot acceleration you will want to go with a sequential twin turbo set up. This is where you use two turbos of dissimilar size. One smaller turbo is used to spool at the lowest rpm possible and then used to spool a slightly larger turbo. This is good for very low rpm boost levels and will give the best out the hole acceleration.
Lastly is a single turbo setup. Here you use a larger, sometimes a much larger turbo, to get the most out of the top end of a motor. Here you will make the most top end horse power, but you will have the most lag coming out of the hole.
So that is why I did not vote cause every set up has it's place, it depends on what you are going to use the car for!
****Note the RB26DETT is a sequential twin turbo set up!****