AP Tristana is the new Mid Meta. Think about it, if all of her abilities (except her Q) scale with AP, then why doesn't she mid? Granted, she would be a better mid if her Q was an ability that dealt magic damage, but her Q makes her E so much better. Who thinks this is a great idea?
It's somewhat viable.
it's viable but i would hate fighting it lol 
just like her
It can be viable. It' used to be really strong and a lot of people did play it, but now AP Tristana is quite a bit weaker since her rework. Her E requires more work to get the maximum damage potential, and her R lost .5 AP scaling (although it still has a 1.0 ratio which is really good). Not to mention, DFG was removed, which definitely hurts AP Tristana.
Overall, AD Tristana is just so much better and useful now since her rework. If you want to give AP Tristana a try, go ahead, it's still viable I'd say, just not that much.
Her AP scaling got nerfed a lot with the rework. Before the rework she was basically the same as leblanc but with higher cooldowns and not as safe. Why pick her over leblanc? Really no reason.
