Sure - I get the pellets just from the ooni website, but I think any eco friendly wood pellets will do (going to try some from Amazon.com next).
Ooni say that it takes around 10 minutes to heat up, but I’ve found it’s more like 20 to reach a steady, optimal heat. You have to add the pellets until it fills up to a point, which can take longer than 10 minutes in my experience. The pizzas cook in like 90 seconds to 2 minutes though, as Squee mentioned, so you save time there. The new gas ones are probably easier to use, but I’m not sure you can take the ceramic stone out and flip it (the heat cleans the bottom of the stone).
Our neighbours occasionally play loud music in their garden, which makes it the perfect time for me to crank up the Ooni and blow baking hot pellet smoke straight into their faces. I tend to overload it with pellets, which creates the thickest, most oppressive smoke clouds. I could ask them to turn it down, but this method results in less confrontation and a pizza.