Lentils used properly make a dish meaty. Used improperly, to the invention of murder.
To answer the OP, it depends. If you use them in a dish where they are allowed to be tasted, then yes (eg, I make a salad of lentils, feta, tomato etc) you can tell a difference. If you just cook them to buggery as is the fate of much lentildom, then no. Even if you can taste that they are different you might struggle in a blind tasting to identify them correctly.