An inverted V is about as close as you're gonna get to an Isotropic, that being a point in space which radiates out spherically exactly the same in all directions and angles.
- Pic from http://w4neq.com/htm/doublet.htm - but keep in mind, that's only 80 feet high on a band where a 1/4 wave is 60' long! This pattern would be equal to an Inverted V for 11m at approx only a 12' high apex! - Try to get it up to 36'-45' if possible.
The higher you get it the better, as in just about ANY antenna installation, but keep in mind when going from a flat-top dipole to a 90° Inverted V, you're losing 3dB in the broadside direction to pick up performance in the perpendicular directions.
PS: At 120° or a 60° angle per side, you'll have the flattest SWR when cut to R=52, X=0.
If you're trying to make an omni out of it, then get it as close to a 90° as possible (a 45° angle for both sides) and yes, HIGH AS YOU CAN!!
Remember, the higher you get it, the longer it will need to be to tune a flat SWR.
*EDIT* - avoid using non-insulator-broken metal guy wire, use dacron covered kevlar if you can.
