Efr turbos are the way to go if you can fit them. Their massively larger than comparable t3 turbos however, and space is already at a premium with tubular manifolds. I know I couldn't fit one with this setup. The gtx3071r is a drop in turbo with my tial vband setup, so it was a no brainer.
The only efr I'd want is a 7163 which is nearly a grand more, and once you figure in a new manifold and down pipe setup I'd be downright stupid to switch.
Lastly, I don't want a turbo that spools too quickly. Having had both a k04 and a gtx28 they both just spun. 4k-ish spool and 500whp potential out of the box makes this a turbo a winner.