The chips, resistors, capacitors etc are all mostly functionally equivalent. The transistors, regulators ICs etc will all do what they're spec'd to do, at a basic level.
Where it gets dicey are fringe cases, and on poorly controlled specs. Care about the temperature drift of your resistor, the slew rate of your op-amp, the beta of that BJT, or the mismatched LED strings in the COB?
Better test it to make sure it'll work for you, because 90% of the time, it's bullshit.
For common parts, it's easy to set up a new line, running off good parts -- the 555 timers and lm317s do enough volume for a new line to make sense. These chips are usually better characterized. If it's a small volume part, or something old as dirt, it's usually pulls, a new part in an old case, or just a normal part remarked.
Where it gets dicey are fringe cases, and on poorly controlled specs. Care about the temperature drift of your resistor, the slew rate of your op-amp, the beta of that BJT, or the mismatched LED strings in the COB?
Better test it to make sure it'll work for you, because 90% of the time, it's bullshit.
For common parts, it's easy to set up a new line, running off good parts -- the 555 timers and lm317s do enough volume for a new line to make sense. These chips are usually better characterized. If it's a small volume part, or something old as dirt, it's usually pulls, a new part in an old case, or just a normal part remarked.