After a lot of experimenting, and realizing where some of my problems with actually losing weight on a normal reduced-calorie diet were (ie. mostly psychological), I've given in and gone back on a low-carb diet as of yesterday. Current weight as of this morning is 268.2 lbs.
I suppose those "psychological problems" need a bit of clarification, since I'm hanging this out for all the world to read. ;-) My basic problem appears to be moderation; I have a hard time not taking something that's "good", and repeating/consuming/perpetuating it long past the point of where it becomes "bad". Take the fuel system I'm currently designing for the car: rather than allowing current plans and a certain amount of "wiggle" room to guide the capacity planning for the system, I'm building a system that will support the largest conceivable combination of parts I might put together. Not because I worry about the cost of doing it twice, which might be a reasonable answer, but because I can. Because it's fun to build things, and thus building something incredibly complicated and expensive must be more fun, right?
It applies to other things too. How many people do you know that run their own web and mail servers at home, complete with backing databases, along with a four-network router/firewall that handles Internet, DMZ, wired, and wireless network traffic, all basically hand-built hardware running Linux? Do I need it? Nope. But what if I wanted to run an ISP from my spare bedroom?
The same unconsciously applies to food: I sit down in a restaurant, look over the menu, and rather than selecting what I need to feel sated, I head straight for what gives me the most enjoyment then-and-there, and which completely satisfies me: a large entree with appetizer and dessert. So, while I have the mental wherewithal to temporarily curb my usual habits, I almost inevitably go back to what seems to be a core personality trait with me: excess.
So, we come back to my goal: lose weight. Ideally, I'd simply change my outlook on life: stop over-engineering, stop driving so fast, stop ordering dessert with every meal. Pragmatically, that's not likely to change anytime soon, so focusing on another route to the goal is in order. Enter Atkins; a low-carb diet allows that level of excess to remain, in that I can eat as much protein as I can handle, but I'm not allowed to have carbs, period, full-stop. Desserts (after the induction phase, anyway) are allowed, as long as I accept that they won't be ice cream and cake, but instead will be more like cream cheeses and such. It was a diet I managed to stay with for almost a year before, until I stopped seeing progress and specifically made the choice to get off of it.
So, we'll see how this goes. The interesting part is that the past few weeks have demonstrated that I'm capable of maintaining a particular weight, so there might actually be hope for me after I complete the "loss" phase of this.