Neither the tablets or the filter will take out dissolved chemicals. Still not a bad idea. I've used both. To be blunt if a filter flows water fast enough to be used as a straw it's not filtering as well as you need it to. So those either don't filter as advertised or they are painfully slow to drink from.
With Aquamira tablets I usually let the water sit overnight, but I think it only requires 2 hours. Still that's a lot of time if you're on the go often.
For filters a Katadyn (spelling) will do a quart of water in a minute or two, but it's a lot larger than the tablets and a mess to use.
Seriously, though, there are a lot of products that advertise to do what you want, but find a decent backpacking store (or even an REI) and get something that isn't a toy.
Edit: just as one more note the lifestraw (and there are plenty of even worse similar products) doesn't filter chemicals, metals, viruses per it's own documentation... and recommends chemical treatment for them.... in the instructions. At 25 bucks you're halfway to a backpacking pump that would last several trips, not several days.