Opinions on ICL, Inrush Current Limiter

I have a friend and technician that works on my vintage tube gear. In my opinion he does very excellent work. However on every amp and preamp whether its ARC D70MKII, D90B, HK-Citation II, Lafayette KT600 etc., he wants to put in a In-rush Current Limiter circuit. I always ask the original designer (i.e., fameous!!) did not employ this circuit, why do you? He is adament about putting one in. It does seem to help the big amps as they slowly come up to power and I have tried to hear a loss in dynamic range but I can't...after it warms up.

So any opinions on this circuit? Should the ICL be put in vintage gear? or was it too expensive?? Are there pros and cons? Thanks any comment would be greatly appreciated. Larry