I prefer protoss for warping in buildings. It's so much easier to just have one probe building all the buildings insted of taking a bunch away from gathering minerals to go build buildings. Plus it allows you to build multiple buildings at the same time no matter how many probes you have. I know that the extra cost of their buildings is what evens it out, but even then it's handy in that you can then focus on other things going on insted of making sure your builders get back to mining once they're done.