Hi Chris,
I'm just in the process of upgrading my B-2 network on my 82 CW's and have recently asked the same question to BEC.
In my situation I have the K51V driver which was only used for a couple of years. I was looking at the possibility of making the 400 HZ mod Chops has recently done on his B network however it's not clear whether the K51V driver can adequately handle this frequency. Even if the K51V could handle the 400 HZ mod I don't believe the B-2 mod has been created (Would be breaking new ground).
I don't believe there's anything wrong with the B-2 network it's just not very common, therefore the B network is a better choice (IMO) as it has proven mods more readily available from people like BEC.
For now I'm simply going to refresh my caps, install a Pyle Pro Horn as Chops has recently done and see what kind of results I get.
I'm sure there are others who are much more knowledeable that will chim in.
Shayne,