Roger, I've been thinking about the R8 engine for a future project.
I've been going back and forth between that or the Mercedes AMG-63. (I'm a Mercedes guy). Go Lewis Hamilton! Both engines match up pretty well to the Grazziano transaxle's gear ratios.
The problem with either of them is that to get a new one will run you in the range of 30k or more. Therefore the logical path would be to buy a low mileage engine and have it rebuilt and brought to "new" specs for around half the cost; maybe less.
But what you're getting with that, compared to the LS hp, is wow factor. It just looks a little more cool to me when you open the hood (or hatch). And oh my god they sound GOOD!
Back to reality...
Again, I am only asking this question out of curiosity as to whether those that have gone with pro build shops felt that they got what they had hope for.
Mike