I haven't tested any of them either but the #3 and #4 I haven't heard them. So far #1 is the most popular when it comes to bitcoin paying jobs for freelancers while #2 is also starting to make its name.
does anyone here know if there are job offers on upwork that pays in bitcoin. ive been meaning to find a work there to earn some btc. id really appreciate it. thanks
You can use the services section of this forum for bitcoin / altcoin payments.