I recently bought a Travel Tap flip-top. Tested it out at home with a few litres of clean water then in the field with a few litres of water from a couple of lochs after which the flow rate shrunk dramatically from quite good to annoyingly slow. The water had a definite colour so some sediment was present. I suspect the filter does not handle that very well.
After only a few days use the whole top began to pop right off the thread when the bottle was squeezed so back it went. Maybe I just had bad luck. I want to like it because (apparently) it filters chemicals as well as bugs. That could be a big plus over the Sawyer.
Haven't decided yet what to replace it with. Might even get another. I mostly do cycle-touring and The Travel Tap fits nicely in a standard bottle cage. Squeezing water for one wasn't hard (while it was working..) but, if you have a lot of water to process, something which can gravity feed might work better for you.
I'd stick with travel tap from drinksafe systems for the same reasons you described, the chemical decontamination.
I've looked into most of the competition and drinksafe does it for me .
The quality Vs price Vs efficiency is hard to beat.
The pull top works fine here after a year of use , still no problems.
Maybe it's the fliptop that has an issue?
The guys there were very helpful , so do contact them , they will put it right!
The flow on mine is still as good now as it was new, and if it was to get clogged its less than £20 for the replacement filter.
Just my 2p
No affiliation, just a happy customer