Thanks. I'm using it for a side project now and have my own layout library which I may consider open sourcing. I started to question if I made the wrong decision if OpenPDF had more momentum!

It's a fine decision. The degree of control you can have is a life saver sometimes, especially if you find you need to produce documents that adhere to specific PDF standards, or need to invent some customised layout element. Allows both the quick and dirty, and the very sophisticated.

You could use both if you want, I've done it in toy projects when evaluating.