gengis is right about one thing.
the earlier models are not equipped with enough lights and needs modification.
the upgraded models seem to have worked out some of the kinks, although it never hurts to add more.
BUT, i have read a post here about some fine plants grown with just the upgraded model AG with no additives or mods.
in my opinion, get the best model if you have money to burn or dont want to put in the effort of building your own, BUT if you have the motivation and don't mind a little research and effort, THEN the money you spend on AG XXX could be used to build a sweet as set up.
i personally got the lowest model and have been adding attachments. now i got the hang of things and i am ready to set up SOG on small scale.
thinking of using the left over AG cups i have to start 4-6 clones.
been working the idea over how to set up for my area.
your choice, are ya lazy or motivated?