Well I have got to say right off the top... and no disrespect to anyone on this thread... come on guys.
API vs. Great River? Humm let me see.... BMW or Mercedes-Benz? Anyone who tells you one is a better car maker than the other is basing this on their own bias. Both are great cars and both get you to the grocery store for beer and chips.
Seriously it's really up to personal taste at this point isn't it?
Ok so that said, for MY personal taste I have a MP2-NV and a rack full of SCA A12's which are VERY API sounding.
The API sound is great, love it but hands down, for my ears and sense of taste coupled with my room and gear on the productions that I make the GR just crushes the API (or any of my other preamps) for versatility. The GR might not be the 1st choice on everything
but it is never 3nd and hardly ever looses 1st place by much.
But as I said, they are both great manufactures and they will both bring home the bacon.