Well, if a garage changes the clutch and the clutch is not at fault, the problem will persist – ask the garage what they believe the issue is.
One of the common symptoms of a worn clutch is that the clutch slips, resulting in loss of power from the engine to the driven wheels, and excessive heating of the clutch due to the friction heat – but you are not suffering this fault.
One test you could perform is to stall the idling engine by letting up the clutch with the handbrake on – but I wouldn’t recommend this test; if the clutch is on the way out, such a test could cause its complete failure.
Other questions that might help diagnose the fault.
Has the clutch biting point changed; is it at extremes of clutch pedal travel?
Is there a very small clutch pedal travel between the clutch being fully disengaged and fully engaged?
Changing between which gears do you suffer clutch judder?
Is the clutch judder only evident when changing down through the gears, or is it present when changing up?
Does it judder when pulling away from rest?