Those are three totally different knives... I'm biased towards the Grips, but the new Crooked River is a great looking knife, and the reviews have been really good so far.
I'm in the minority, but I've never been a fan of the 710. That said, it is probably one of BM's biggest sellers and it has been around for a long time, so that says a lot about the knife...
The G-10 totally changed the Grips. I don't have a problem with the "plastic" handles, I think they are part of what makes a Griptilian a Griptilian, but the G-10 gives the knife a totally different feel,
and the open back with spacers really adds to the look of the knife.
It's a very personal choice and it really depends on what you are going to use the knife for. Personally I think the Grip and Crooked River are better choices for hard use, but
I don't think you could go wrong with any of your choices, but if size is an issue, the CR and 710 are bigger (longer) knives than the Griptilian