Oh yes my curation has definitely doubled with the delegation, the delegation pretty much doubled the amount of hive I had, so when the delegation is over, my curation should stay about 50% higher than it was pre-delegation, that is still to be seen however.
Yes higher HBD means I can buy more Hive. I am still doing the conversion route instead of buy direct, I did a couple of checks and I did get a tiny bit more hive through the conversion process than the market direct buy. But as you said, every tiny bit helps.