A lot of what you said just isn't right at all. Blindsight doesn't give you the ability to see through or around walls. It's stated that line of effect is needed. Also I'm not sure what you mean by terrain features, but blindsense as a whole isn't blocked by certain terrains. Sometimes this is the case, but it's more based on creature to creature, like sharks only have blind sense in the water. Although you could say that a vaccum blocks blindsense, but that also block blindsight.<br/><br/>Basically what differs blindsight from blindsense is blindsight lets you "see" as well as a sighted creature would, with the exception of colors and writing. Blindsense is much more basic like you kinda know what things look like and where they are. That's why you still have to be careful while crossing uneven terrain, and can't see concealed attackers attacks as well. Most creatures with blindsense have other sights that go along with them, because blindsense really can stand along as a way of detection like blindsight can. Lots of creatures with blindsight just don't have another type of vision because as the name implies blindsight is a type of sight.