I have the B2 9x45 and actually sold a Leica Duovid in favor of the Maven. It is terrific for me. Size of the bino has never bothered me while hunting. On paper it seems bulky and heavy, but in field use, I have never thought they were too big. Balance is very good for my hands and they are easy to hold steady at 9x. I love them on a good tripod as well. I carry them in a Kuiu harness.
Three of my buddies have the same B2 but chose the 11x configuration. The Depth of Field is better on my 9x and the 9x is brighter, but both offer terrific color rendition, excellent detail and a sharp image.
I also own a B3 8x30 now as I wanted one for archery 3D shoots etc. And I have a C1 8x42 that I bought for my son to use. The B3, even in its small package, is brighter, sharper and all together better than the C1. The C1 was kept after a thorough comparison to a Vortex Viper HD. Only real knock on the C1 to me is the FOV being narrow. Not a problem at all in the B3 and especially the B2 9x.
Haven't tried the B1 bino, but I sure do read a lot of good. I compared the two at the hunt expo before buying the B2 upon the recommendation of the folks at Maven. Happy with my decision.