So, here's the assertion I made on Twitter yesterday, for all to see: 4e is easier for me to run than Risus. Risus is just abut the simplest RPG I know that I still consider functional, so this is a specific example of a generalization, that 4e is the easiest game for me to GM.
Obviously, that's stupid.
The reality is that the rules of Risus are shorter than the blog post is going to be. In contrast, 4e is a MASSIVE amount of rules content to be read, absorbed and implemented. How could 4e be easier?
So, first and foremost let's set aside how easy or hard the system is to learn. That may impact adoption, but it doesn't impact how much work it is to run. 4e Still has lots of rules, but let's not worry about how long it takes to read them.
Similarly, let's set aside skill and just assume a high level of rules familiarity, whether it be with Risus, 4e or whatever game you are comparing it to in your head. This doesn't mean having all the rules in brain, but rather that you have enough rules that rules questions don't negatively impact play. Whether you pull this off through knowledge or technique doesn't really matter. Plus, frankly, if I were talking about the role of system mastery, I'd probably be more inclined towards games I wrote.
So here's the thing - Risus is unquestionably _simpler_ than 4e. That means that a lot of tasks (adjudication, resolution and bookkeeping) are a lot faster and have fewer moving parts. A fight in Risus can be finished in a matter of minutes while the same fight in 4e might take an hour or more. At first blush, that seems like a strike against D&D, but take a moment to zoom back to the large question, that of effort.
Let's take as our baseline that great adventuring staple, the dungeon crawl. It is, I hope, a given that 4e is pretty well designed for this sort of game, so I don't need to do much for it. In contrast, Risus is going make for an interesting time with the same dungeon because, frankly, it will be a hell of a lot more boring. Fights in Risus are not interesting in and of themselves - they're interesting because of the context, the stakes, and the player investment in the situation. Risus is just a resolution layer on top of those things, and as a result you'll find that Risus dungeon crawls tend to be much shorter than those in 4e.
From a certain perspective, that remains a great argument in favor of Risus, but again, let's zoom back to what's really going on. I, as a person, want to create an entertaining experience for my friends for the next, say, three to four hours, but I'm tired and drained (and maybe old and drunk) so I'm not really on my game. This is where things start going wrong. The apparent ease of Risus starts becoming a burden because all that speed, efficiency and focus means more work for me.
In contrast, consider the 4e Game. If I must do prep, it's about as complicated as ordering dinner (Go to DDI, find some monsters of the right level, print and go). It's more work to dig out the minis and maps than it is to come up with fodder for 2 or 3 encounters, and the rub is that 2 or 3 encounters is, in 4e, a pretty full session. 4e fills the time, and for the tired, lazy GM, that's a godsend.
Now, there are lots of other games with long combats, some with simpler rules than 4e, so what makes 4e stand out? Honestly, it's that once the fight starts, I can lean on the system to do a lot of the things the GM would normally have to do to keep a fight interesting. Pacing, balance, spotlight, dynamism - these all will flow naturally in a 4e fight, even in one designed with half a brain.
In short, 4e provides the greatest payout for the least amount of work.
But (and of course there's a but) don't draw too many conclusions from that. It doesn't mean, for example, that 4e offers the most bang for your buck, at least in part because the work to payoff ratio drops off almost immediately. The strength of te infrastructure becomes something you eventually have to work against to achieve your goal.
There is a point (for me) where putting the same effort into a Risus game and a 4e game produces a better Risus game, but that point is definitely somewhere past the brain-dead, bone tired state where I really wish I was playing 4e because it would make my life much easier.