A few years ago, when I started printing, I learnt from a supplier of Water base used for roller printing in the textile industry. These guys order in tons.
They supplied me chemicals and a recipe and I'd make my own base and add pigments. Very cheap.
Water base sounds very environmentally friendly but it had formaldehyde and all sorts of nasty chemicals in it. (Not sure if it still does)
For printing on white it's great, not so good for darks.
In a hot climate it dries on the screen fast and you can't use your short infra-red oven that works well with plastisol. The base I was using needed 5min in the oven.
Plastisol has so many advantages, you can keep a stock of Pantone matched plastisol, You can stop in the middle of a job and have a break, carry on tomorrow or after the weekend.
Not so with water base.
Correct on light garments it has a soft feel, especially after being washed but with thin meshes you can get a softer feel using plastisol.
I personally think Plastisol is more environmentally friendly. We don't throw plastisol down the drain, we clean the screen with cards and very little ink gets washed into the drain with the emulsion. With a good filter you trap most of the plastisol. With water base you have to wash all the screens after use with water.