It has some issues and it is not perfect, it has a DC offset at the output and it has very low power output capabilities. The output impedance is too high to power anything but as a basic low power signal source it is fine. I highly suggest building a current or power amplifier to go along side it to get more power. For the price it is a really good learning tool if you have an oscilloscope and since you are adjusting the function gen blindly without a scope it is not that useful. You could even use your phone for a function gen but this does have the advantage of better frequency range and probablyt better rise/fall times making it fast. It has its place but it is not a precision intrsument, just a hobby learning tool, try to use a capacitor in series at the output to remove the offset

PB is good quality and there is no major problem mouting it
Some gotchas :
* The square output is not modulated by the amplitude pot, it will always be maximum. I searched a long time for that.
* The bolts are BELOW the pcb, that's why the internal screws look too short. They are just there for alignment, The PCB is hold back by the pots being sandwitched by the case (see pics, i used nylon screws but they are ~ same size as the provided ones)
* you can add a led + ~ 1k resistor a tthe top of R3/R5 (R3 is VCC, R5 is GND)
* The pots are not all the same, one is 100k, the 2 others are 50k