I can personally speak about the Picco. They make lots of torque, they're easy to break-in, they're easy to start and their plugs last for a long time between changes. I had a JL Evo3 which I ran three gallons through with a new rod at each gallon that still makes plenty of power and has no loss of compression.

The Picco Evo4 is even better because it makes even more torque than the Evo3. I've ran almost 3 gallons without needing a rod change like the Evo3. For just $30 more than the STS, you can get a Picco Evo4 Edo also available through RC Mushroom.