Jon Ulmer from The Electronic Intifada, IMO, is the single best source on the tactical / ground level of this conflict. He is saying that a lot of unexploded Israeli bombs from the 2014 bombardments and from this conflict's are being cut open and TNT reused. He is also saying that the Gazans have virtually unlimited supply of lethal rifles which can pierce even light armor on vehicles and he is citing two Israeli soldiers recently killed with just one shot.
Doesn't look good at all for the IDF presence in Gaza. Well worth watching if you want to understand the Gazans capabilities: