The Ti-Tri system is fine... assuming that you have a relatively easy source of nice dry twigs to load in there. Collecting twigs might take only a few minutes. If it has been raining or if the twigs are damp, you might still get a burn, but it might be slow to catch, slow to heat, and extra smoky. If your twigs are some bad variety of wood, it could be worse. If you get above timberline, there may be zero twigs to burn, or some park regulations might prohibit wood fires. That is the good thing about this system, in that you can burn alcohol or Esbit for the meals when you only have bad twigs. When I burn my titanium pot with good dry twigs, it works great. When all I have are damp twigs, it leaves a lot of sticky black creosote on the pot. So, there are no show-stoppers, but there are little inconveniences if conditions aren't right.
In early May, I was melting snow with mine. Slow, but OK.