Great topic! I'm not a huge fan of dating apps, probably because I live in a big city and most people use these apps just to hook up.
As far as speaking before meeting, I usually like to text at least for a few days but not like 24/7 texting. I don't like texting too long before meeting though because then I feel like the guy doesn't want to meet up at all.
I agree that 'texting chemistry' can be misleading. I once matched with this guy on Tinder, we texted for a few days - very kind, he planned the date and everything but zero chemistry when we met, at least from my end.