It's not often that I offer praise for Tory politicians, and indeed David and I had many political arguments over the years on issues such as social housing, taxation, renewable energy and more.
But since politics so often looks just like a bunch of middle-aged (mostly) men shouting at each other and never listening, it's important to acknowledge that disagreeing with someone isn't the same as disliking them.
In fact, I find it all too easy to argue with someone I dislike.
I think it's far more stimulating, rewarding and useful to have a political disagreement with someone I like and respect; someone who brings intelligence, wit and decency to the argument.
Politics needs those qualities across all parts of the political spectrum. That's what I appreciated about my arguments with David - it felt like a privilege to debate against him.
On the occasions when we were on the same side (there were a few, like our criticisms of recent laws on sectarianism at football matches) I always knew that the standard of his debate would challenge me to raise my own game too.
There are times at Holyrood (and I'm sure this is true of Westminster too) when a member simply reads out a speech written by researchers, without engaging in the cut and thrust of the debate.
There are times when a member asks a question but all too clearly doesn't begin to understand the answer. In short, times when our standard of debate is poor.
David McLetchie was the polar opposite. He was the kind of MSP who could elevate a debate on almost any subject, and I don't think I ever heard him open his mouth without it being clear that he knew his stuff.
If our Parliament is to do its job to a high standard - holding the government to account, scrutinising legislation, challenging Ministers and other decision makers, and representing the voters as best we can - then we need people like David McLetchie.
I think our Parliament is poorer for his loss.