They're fun little things, but don't expect anything fantastic out of the box.
Hop is very weak, and struggles to lift anything over a 0.25.
You can shim the arm to increase it, but then it's trial and error to find what works for your weight.
I had it over-hopping 0.3s, so it's possible but takes time to sort.
I bought the PDI extended barrel to give a little boost in power, as shown below.
You can also get the 15 round mags too.