Allie:
I haven't made any Heron Bay kits, so it's tough to have a favourite. There's a new HBS near me that carries the HB kits, so that might change. Although initially I am probably mostly interested in the Limited Editions that come out in the fall and winter months (North American fall and winter, that is).
The two main tweaks that I employ are
1) changes to oaking - usually reduction or elimination as we are not fans of BIG OAK
2) increased time frames once in carboy
If a kit comes with a Suss Reserve for sweetening, I usually add it to the primary instead of after the sorbate. That's because we prefer dry wines.
I haven't experimented with adding elderberries or raisins or bananas to kits that didn't come with them. As a rule I would be more likely to do that kind of tweak to the smaller 4-week kits than the bigger 6+ week kits.
Steve