i have only found 2 disadvantages to the cubes compared to bigger tanks...i am very limited as to stocking options and aquascaping a smaller area can be challenging. but i can live with that because i do get a lot of enjoyment out of my mini tanks.
I don't mean to start the argument again or whatever, but I think what you guys are demonstrating is just two different hobbies.
You are no less a hobbyist for not enjoying the maintenance and details. You are actually more of a "dual hobbyist" when you do. I don't think this breaks into small tanks versus large, although the folks who enjoy the details and tinkering tend to "need" larger tanks to fulfill that part of their "dual hobby"
As an example. I started with a 60 gallon, not drilled, no skimmer, just LR and a canister. I eventually added an HOB skimmer, and starting wanting to keep things that would require water quality that I couldn't maintain without an excess amount of work on my part, or loads of equipment IN my tank, or hanging on the side of the tank that would invariably seem to ruin the "view", and therefore basically make it useless endeavor, since there isn't much point in high end SPS or clams or whatever if you can't see them.
What I noted at that point was that I had a choice. I could up my "work load" and equipment to get closer to what I wanted, or take my hobby in a different direction. I could spend my time understanding what WOULD be happy in my tank. I could sacrifice high end SPS for something a little more forgiving, which isn't that much of a sacrifice in the end really, and I could enjoy my lower maintenance schedule and tank. That, in and of itself if a hobby, researching and understanding what you can/should maintain in your tank. Understanding its capabilities....
OR, I could upgrade and start playing with all the gadgets and toys available with a drilled tank. I did both actually. My 75 isn't much bigger than my 60, but being drilled I have more room to play. I added a controller to the 75, can run an ATO without it being unsightly, dosing pumps, reactors, etc.. Here is where I really see the difference. I love both (all) my tanks. The 60 is an awesome low maintenance tank and were it all I had, I most definitely would still consider myself a hobbyist. The thing is, what really happened with the 75 is that I picked up a brand new hobby. That hobby is tweaking equipment, playing with levels, reading about new equipment that I can run... Re-learning the basics almost with a new approach. I'm no more or no less a hobbyist for having the 75. I've picked up what is a related, but new hobby.
So, yes, I agree in a way that the cubes are a beginner tank, and they can only take you so far. If what you want is the "tank hobby", they can be perfect. If you want the "tinkering and equipment hobby", they will fall short.
Again, I'm not up for re-starting the argument. I "think" I see both sides here, but in reality, my perception of both sides couldn't be completely inaccurate. I do my comments speak towards an AIO vs custom tank in a way and hope that that means regardless my comments might be helpful to the OP, so....