Have a while ago, been meaning to get back onto it - worth it. If you take it properly you can basically get an extra couple of reps, just make sure you're drinking lots of water.
Best way to test it out is do a 'loading' phase which means smashing down like 25g a day of the stuff (read up some propper guides) for like a week to get it in your system - record your lifts before and after that week you'll notice a difference. That said I'm too lazy and forget to have it now. Most just do 5g a day every day.
Pre workout is weird again, my ears and face start getting itchy on the way to gym lol
But yea most more serious gym goers recommend both from what I've seen / read.