They are a pretty good budget amp.
However, for the best bang for buck, you can't go past Jaycar's range of amps...
2x100wrms = $225
4x50wrms = $260
2x150wrms = $330
4x100wrms = $360..
They are built well, all have low/high pass filters and like I said, best amp, bang for buck.. Good for subs..
Also, Coustic amps are also pretty good amps for the price tag.