Agreed! the B4 is great.
The trick with tall lipos (25mm in height I mean) is to use a B4.1/B4.2 rear shock tower which was designed to allow Lipo fitment. My thumb screws seem ok with the carbon brace and this tower, so far???
there is a picture of mine with lipo fitted halfway down this thread. I now use the carbon battery brace instead of the brass one.
http://www.oople.com/forums/showthread.php?t=160834&
hope this helps.