I would go for the water bottle rather than the straw, it costs £20 more but you can filter an extra 1400L with it, you also get nearly a litre of water storage too so thats an added bonus.
Lets hope santa puts one in my stocking this xmas
The filter I have at the min is the MSR miniworks EX, although its very good I still like the idea of having a filter integrated into the water bottle.

