Mho
I have a previous version of the Thunderhead System III, as well as a Moonstone paclite and a North Face XCR Mountain Light Parka. My ratings and uses:
Thunderhead- waterproof, not super breathable, light, inexpensive, medium tear resistance
Paclite- waterproof , breathable, ultralite, expensive, limited tear resistance
Gore tex XCR - waterproof, breathable, heavier, expensive. good tear resistance
Mountain Light for me is too heavy and warm for the hiking trail but great for the downhill ski trail. Thunderhead is less breathable but more sturdy than paclite - will keep you dry from the outside but if you produce a lot of moisture you may be dissappointed with the inside moisture. Paclite is great for open trails, but would stay away from trailless peaks and bushwacking or you might be poked full of holes. If you tend to be a cold person the gore tex XCR may work for you with good venting.
For $35 you can't go wrong with the Thunderhead.