Well initial testing conducted, I basically Beasted the [Bushcooker] against a Meth stove [Decagon] and a Gas stove [Coleman Alpine].
In my non scientific pursuit the ultimate cooker set (for me anyway) I had set the challenge as a race to the boil (properly..... on a rolling boil etc) 1.1 litres (or what ever fits) in a Tibetian 1100 Ti kettle.
All tests were outside, its was cold but not freezing, so about 3-4 degree's, all water was drawn from outside tap and as such also probably not a dissimilar temp.
Meths, had to fill decagon completely twice - didn't measure fuel exactly if anyones bothered I will re-measure, Small Foil wind break employe - 18mins, not including time to prime stove/jets
Buskcooker, fueled on air dry garden twigs, most smaller Dia than pencil, a bit damp - 2 good handfulls and a few bits of pine cone lying around - 15mins, some issue with keeping good fire heart going, not including lighting initial fire
Unhappy with this result and confident record could be broken I has another go - with more attention spent on keeping a good fire going - at the expense of fuel, also no damp fir cones etc - 15mins or near as damt it!, still not perfected the feed times!
Right - this time I decided to use only dry Tinder type wood, lifted from indoor wood stack, soft/Hard type mixture batoned down to 7-10mm squares, about 40mm long, not very bushcraft (i.e cold/wet winters day) - feed the fire constantly, no concern about carbon foot print - Just under 8 minutes!!
So now pleased with the potential (8mins with dry fuel), and the security of knowing It was possible to boil a litre of water with twigs from a hedge in the middle of winter I decided to try my old Colman Gas stove.
No foil wind break - New gas cartridge (small one) - was expecting 5 min's, got just over 7!
Excellent - couldn't really beat that time with the Gas stove, specific Gas burner/bowl combo would be faster but so wold using a different (non Ti) kettle!!
My opinion today is that bush cooker is great - needs more attention and constant fettling over other methods - which is nice actually - long term concerns are robustness (crushed in bag?) and rust/corrosion - overall would recommend this charming a viable option even if its not your primary stove!