How are you firing? In my opinion the reason I was able to get the little oven hot so fast was that I could completely fill it with wood. My best results came from building a cabin in the middle AND a ring around the perimeter of splits stacked like fallen dominoes if that makes sense. I could light it and walk away. The perimeter wood would burn last and once it was done it was ballistic.
I have basically used three different approaches:
1. Start with a fire in the center. I stack 4 logs in a square, each leaning on the next, so that one end of the log is raised up, and the other end is on the floor (like falling dominos). Put some kindle on top of that, put 2 or 3 logs on top of that.
Once the fire is up and running well, say 20 minutes or so, start adding logs so that I build a large blazing fire.
2. The same as what you described. Same as number 1 in the center, but also a semi-circle of logs around the perimeter. Also, stacked end to end with one end resting on another log, the other end on the floor.
3. Same as 1 (or 2 - does not matter much) - stuff the heck out of the oven with logs and keep stuffing. This is the way I did the last two the same as each other. It did heat up the fastest, but left the most coals.
I have started all of the fires with one of those little Weber fire cubes. They seem to work nicely.
So, when I followed number 2, it did all burn well and the like. It was just that the oven, (as measured by the FGM thermometer) was no where close to "ballistic." Roughly speaking, except for the last 2 firings where I really stuffed it, the oven would heat up by about 130 degrees C in the first hour and the 100 per hour thereafter. Since I was striving for a minimum of 425 (about 800 F), this takes somewhere around 4 hours. Then I need to get the coals out, bank it, throw a log or two on the banked coals, and let it stabilize. Now it is 4 1/2 or so. The last two times, where I cut it down to 4 was "fast".
After the last bake, I filled the oven to the brim with logs (the oven was over 200 C) and put the insulated door on. So, they should be nice and dry when I fire the oven. I also have a small load of oak (bought a bit to try it out instead of the almond).
Any ideas on an approach this weekend?