All of my Neutrons have flown nicely so far, with my favorite being the 176 fairly domey lime that is in the water of #20 on my home course...It started out a little beefier than the flatter proton eclipses I had bought prior to receiving it.
My most OS is a clear FR with tons of dome and high plh. It was my first Vector and made me think they were all that OS.
Your best bet would probably be asking for the heaviest, domiest one a shop has in whatever plastic you feel like trying. I've seen variations in dome and plh to some degree in all types of Vectors, but from my limited sample size eclipse tend to be flatter, while Neutrons so far all have had moderate dome, and FR protons all seemed on the domier side. I don't have any regular protons from the later runs though.