I have a serious case of MTS and
I use chlorinated town water.
My biggest tank is 125g and has big messy fish - so it gets big water changes (usually 75%, hopefully weekly, often bi-weekly).
I dechlorinate as I fill - using "Tap Water Conditioner" brand - its a drop to a gallon, a capfull to 100g, something like 9000 g per bottle.
Biggest issue I've run into with town water is the chemistry - I have really really soft water (which some fish love, some fish hate) loaded with phosphate.
If I don't keep up with my water changes my pH plummets - I have some tanks I keep around 6.5, some I try to keep around 7, the big one I'd like to keep just over 7 but it often gets down below 7, and one tank I keep the pH around 7.8.
The extra phosphate means that if I'm lax about maint (or overfeed) - I get gobs and gobs of algae. Having lots of live plants helps, but I still battle the algae monster.
Good news - fish that love soft water love my water, and its easier/cheaper to harden soft water than it is to soften hard water
Its new, its improved (its still a work-in-progress)