I agree with Hikemor. There is no real difference between different types of materials for water bottles or other cook gear when it comes to boiling or cooking times. Some higher end SS pots have thicker bottoms, but again not enough to make any real measurable difference.

As for TI water bottles...or any other TI gear in general, I don't bother. Carefully and thoughtfully selecting and packing your gear for the expected distance, weather, terrain and environment can easily make up the difference in weight. Too many times, I see people out for a day or overnight hike and being weighed down with too much gear that would be more suited for an expedition length trip.