I've used the Happ amp and found it to be fine. It depends what you want from your sound system though. If you are looking for primarily gaming audio with some music use, then this is ideal. It's simple to mount, very robust and a easy to wire up. If you fit the right cones (3" or 4") into enclosures, you'll get a good sound with reasonable depth.
On the 2.1 side, I have only one experience and found the setup way too bass-heavy and severely lacking mid-range.