Is 5-speed better than OD?

[Tab Julius <tab@penworks.com>]

I'm looking to add OD to my '78B, having been so encouraged by everyone 
I've asked.

However, I've become aware of a 5-speed conversion kit for the B.  It's 
considerably more expensive than the OD, though.

Anyone try it?  Would it be preferably over the OD?  Enough to justify the 
difference in cost?  What about difficulty/time changing to 5-speed over 
installing an OD?

Thanks in advance,

- Tab