My opinion is a wee bit different then Steves... But we all have our own
Not expensive? He just listed parts over $250 and didnt even mention them all or any cheaper option.. CO2 systems are often the most expensive parts of a planted tank (but dont have to be, see below). Also he forgot to add two critical pieces of equipment (for the type of setup he is describing). A needle valve and a solenoid to automate it.
Not confusing? Sure its not confusing once you have one and have used it and know whats going on, but buying 10 pieces equipment, making sure it will all jive and work properly can be just that, Confusing. Not to mention dealing with pressures that can be dangerous makes many of us hesitant.
Personally I went with a premium GLA system for my first setup and I couldnt be happier with the quality, the instructions, and support I received. Yes it was expensive, but teh support it comes with and the knowledge I learned was well worth it.
Look on the for sale forum, there is a lot of member selling paint ball setups for $40-60 and all you need is a $15-20 paint ball tank. this comes with everything to get started except a solenoid. this works great as a beginner setup. The GLA one you are referring to is nice as well and should also do a good job, plus comes with great support and information. Then later you can decide if you want some of the benefits that some of the nicer systems offer.
Hope an alternative opinion helps you figure it out