The original BurnProof created gaps up to 45 micron long when the writing laser was stopped.
The newer BurnProof II reduces the gap from 45 microns to 5 microns in order to compete with Richoh's JustLink techonology, which creates gaps of only 6 microns.
In terms of actual CD reads, any CD drive will ignore gaps up to 100 microns in length, so really it doesn't matter. It makes no difference to readability, quality or life of the disc.
About the only thing I can think of is reduced write capacity with the old BurnProof, as more space is wasted. But this is not even a factor worth considering unless you had several bufffer under-run related stops every second while writing. The technology itself prevents this from happening anyway.