To date, I've simplified the stove to a minimum using materials readily available. FOM ranges from .85 to .95. Burn time is typically between 1hr 30 min. After some 60 trials with various configurations, I'm pretty happy with this. Familiarisation with the stove's operation is necessary in order to avoid some very impressive amounts of smoke.
Wind resistance is good.
Flame holding is not a problem, though again, the operator must understand a few basic techniques. I've not tried wet wood, but assume this would negatively affect flame holding. I've used both hard and soft woods in the stove with little observed difference other than bulk density. The stove incorporates a perforated fuel cell insert attached to the removable bottom 'lid' which is 2 cm distant from the inside wall of the stove. Average fuel load is 4.5 kg of loosely packed dry wood cut neatly in lengths of 27 cm, which is the inside depth of the fuel cell.