D&D 5E A quick run to the top!

[AriochQ]

My group plays monthly in 6 hour sessions. We have been playing about a year and they are 5th/6th level. So, like the poster above, we are at about a 1/4 of your rate.

I am not adverse to high level campaign, but I think there is also something to be said for a 'smell the flowers' approach. Fun can be had at any level. Personally, I like the mid levels best. At low levels, characters are able to be knocked out too easy and have a limited set of actions to choose from. At high levels, DMing becomes more involved/time consuming as the monsters tend to get more complex and the characters sphere of influence within the campaign world gets bigger. At mid level, characters have a variety of options since they have unlocked many class features and characters can begin to influence regional events, which is why I find it most enjoyable to DM.

 

[Sunseeker]

I'll sort of generally respond with a couple thoughts.
1: We run fast. I have fairly skilled players who, even when working with complex characters, can take their turns in 30 seconds or less.
2: I have a small group (3), which has led to more encounters, with more XP being awarded (when I review my math, since I don't really use XP for anything other than an encounter guideline)
3: "Encounters" include non-combat events, I use some guidelines from 4E for this, so I'd posit that perhaps, 3-4 levels were awarded for completing events that did not require combat (or the players chose to resolve the events without combat). So for XP comparisons, maybe a reduction of 1/4th?
4: I run my enemies fast, often with group attacks. I can generally complete all the actions of a 5-6 monster attack within a minute or so.
5: Exploration is accomplished with some light RP and Survival checks, so the game doesn't get slowed down.

But yes, we run pretty fast and try not to get bogged down with needless things. Pretty much anything you can do, explore or interact with is relevant to the game I don't want to describe distractions, so I don't include them.

 

[Hussar]

Oh, hey, please don't take what I said as a criticism. It certainly wasn't meant that way. I'm actually really impressed when groups can accelerate the pace to this degree.