To reinforce this: pandoc has been the go-to for a long, long time and they have encountered and addressed tons of issues, which is especially important for two underspecified and over-provisioned formats like HTML and pdf.

Go through the revision and bug history to see a sample of issues you're avoiding by using a highly-trafficked, well-supported solution.

The only reason not to use it is when they say they don't support a given feature that you need; and the nice thing there is that they'll usually say it, and have a good reason why.

The other reason to use pandoc is that while you might currently want PDF as your outbound format, you might end up preferring some other format (structured logically instead of by layout); with pandoc that change would be easy.

Finally, pandoc is extensible. If you do find that you want different output in some respect, you can easily write an plugin (in python or haskel or ...) to make exactly the tweak you need.