Good things about the Aeropress:

1. It's faster and easier than a french press or coffee pot, and faster to clean.

2. Paper coffee filters remove carciogens, and forcing coffee through a filter is quicker than dripping.

3. The 'breach unloading' design makes it super fast to clean.

4. The surface area to volume ratio keeps the water warmer during brewing.

5. The plastic design is good for camping, but not daily use in the kitchen.

6. The plunger works extremely well, takes a very long time to wear, and is also easy to clean.

Bad things:

1. A wet filter paper and twisting action isn't a good combination. The pressure/force from the main tube body on the filter needs to be minimal, just touching sufficiently for coffee grounds not to get through.

2. The tube wears out, coffee is abrasive.

3. If the current cap had a slight taper internally, and twisting the cap on would compressed the tube radially against the cap, it would create a radial seal. This way, the side leak problem would be reduced or eliminated. The edge holes on the cap could be eliminated, making it easier to clean.

Useful principles for the new design:

1. Glass tubes made of pyrex / borosilicate are inexpensive.

2. The pressing action should work to improve the seal, not fight against it.

3. When things go wrong and wear out, they should fail gracefully, not dangerously.

4. Kilner jars / quick release clamping action could be useful. Bonding to glass needs further investigation.

5. By using a honeycomb hexagonal hole pattern, hole count and hole area can be increased 25% with a comparable hole pitch and diameter, or possibly 40% with further design tweaking.