The Garrett G30-660 is a different choice, I know. I was able to buy it for $1k and couldn't pass that up. A few reasons why this could work well.
First, it has a smaller compressor wheel / faster spool than the GT3076R (the turbo I think most people run). That also makes it a little more compact and easier to fit in side mount.
It's true that these new turbos are optimized for high boost, but actually the compressor maps have a huge sweet spot. Here's a comparison:
GT3076R
G30-660
The red dots and line are from 3,000-6,000 rpm with boost building to keep peak torque low at lower RPMs. The yellow dots and line are the same except at 0ft elevation (I'm at 5,000 ft). The blue dot is a higher peak boost scenario
I don't have a turbine housing yet and I'm really not sure if I should go with a 0.83 or a 0.61 AR. Any thoughts?