Here's an interesting blog post about the Covenanters, by an Australian couple who now live in Oxford. Very similar reaction to mine having visited St Giles' Cathedral in Edinburgh earlier this year:
We wandered down to St Giles Cathedral, because we had read somewhere that Knox had pastored a church there for a while. We found a statue of him in a corner. He looked out of place, among all the fancy stained glass windows and such. It seemed poignant somehow, having him stand, holding his Bible, poised as a preacher. He looks unimpressive amongst the trappings of the cathedral and no attention is drawn to him.
Yet so many people know God because of him. So many people are safe from God's anger forever because he preached the message of Jesus faithfully.
On the opposite side of the cathedral, they engage in activities that would have made him very cross indeed. Lighting candles instead of praying to God. Ostentatious organ playing (and I like organ music, but this was way over the top). Large, audacious stained glass windows. I suspect he would smash his own statue, and then set to work getting rid of all these other distractions to hearing God's word and taking it seriously.