Lithl, I was in getting some food for the family this evening and looked at your signature picture. My five yr old is presently into My Little Pony on Netflix, so as I'm waiting for the order, looked at your signature picture and thought, hmmm I can name half those ponies. Totally not on topic, but thought that was pretty funny.
Well I am glad you agree on EDH stapley type stuff, but when your decks just have the same ol mana rocks, counter spells and such your decks start to become homogenized and feel the same. Instead of putting Thran Dynamo and or Sol Ring in every deck, why not put more synergistic cards that fit at least thematically with your commander? At the very least it will inspire some creativity instead of the same tired EDH cards that have no flavor or thought put into them.
I have to agree. Although budget is a huge driving factor for me having only three decks, I also don't like the idea of too many of the same card in every deck. But I see where toctheyounger77 is coming from. Rocks, ramp, certain answers (staples), and counters in competitve metas to a degree make up the frame of the car, but the engine and tires (theme and cards that actually win) make a huge difference between a Porsche, muscle car, or a monster truck. Lame metaphor, obviously, but it serves my point.
I have only three decks built. I had five, but two were hopelessly over-themed, and not very good in actual play. I converted one to a simpler Simic color scheme, demoted one to 65 cards, and then demoted a second to 65 because it was too hopelessly dependent on tutors and didn't work very well without them. I actually like the three I have now because we don't play edh all the time...just enough to take a break from other formats, but I really like all three. So, passion, budget, travel capacity, and frequency all play a part in what the right # should be.