To me sb, a buy is a buy. If I fill on bid the ask or in between, I am still a long holder taking shares from a short term trader.
If I am on the bid, I would be building up the floor/support with bid size showing strength. If I buy at the ask we break down resistance at the ceiling so there is a benefit both ways.
BTW, even though I have been here since early April, I have rarely set an order for $ABMC below the ask so I don't have that personal experience on this ticker which is why I am asking all the ABMC'ers for your experiences.