The standard TechShop laser here in Austin is the AWESOME Trotec Speedy 300, far more powerful than the Epilog 40W laser that we had at Resistor. However, that's meant having to adjust my settings for various materials with a lot of trial and error.
Here's some values that worked pretty well:
5.2mm birch plywood: for cutting, use one pass 100% power, 0.70 velocity, and 1000 PPI. For relief engraving, use 60% power, 20 velocity, and 1000 PPI.
1/4" MDF board: this took a lot of tries, as it's very dense with lots of layers to cut through and also tends to smoke and flare up. I would end up having to do run after run which would scorch the material. No fun. What ultimately worked for cutting was 100% power at 2.0 velocity for five passes, each one adjusting the Z-axis offset 0.05". That was fast enough to not flare up as badly, and adjusting the height kept the laser cutting the bottom layers of material instead of just burning the sides.