Ginger and some of the other EBers out there have done a great job.
I suggest you purchase at least one. Set it up EXACTLY as the directions instruct, no changing of anything. Then you can decide if you want to try building your own or buying more EBs. OZBO usually has them for mid thirties and the flat rate shipping is cheap. Add me to the list of those that A) LOVE Earthbox and B) do not own stock! Invariably, those that have trouble or less than stellar results have decided to try and "improve" on the system or have made a mistake in setup.
The plastic covering is also important to avoid getting your fertilizer strip wet when it rains. If that happens, a high dose of nutrients can be released all at once.
FYI I just finished eating the most fab BLT with a Brandyboy tomato grown in one of my EBs and Provolone cheese. It was to die for.
