We live in modern times and and have the advantage of the latest window technology. Double and triple glazing, better heat and sound insulation, and best of all - huge windows allowing uninterrupted views...
So why on earth would you decide to cover these perfectly good, large windows with "faux" lead!!
No it doesn't make your 1930s terrace look like a middle age castle, inside it feels like you're living in a prison and makes you look like a numpty with questionable taste! 
... Sorry, I felt like a rant as we bought a house with leaded windows and of course it isn't really cost effective to replace them. So we're stuck with the lead, and every time I look out a tiny piece of me dies.