Actually I'm a big hardstyle fan and I have been to several festivals.
A lot of artists are Dutch e.a. Headhunterz, Psyko Punkz, Wildstylez, Noisecontrollers, D-block and St-eFan.
I've been into the hardstyle scene since 2010 and still love the melodies.
People tend to divide hardstyle into several streams like:
Mainstream (these are the most common artists)
Dubstyle (Imo the worst stream)
Raw Hardstyle (strong kicks and sometimes close to Hardcore)
Early Hardstyle (My favorite).
The most common mistake is that people don't know the difference between hardstyle and hardcore.
Hardstyle is around 150 bpm (beats per minute) while Hardcore is approx 180 bpm.
If you wish to listen to some good Hardstyle mixes try to find some livesets on youtube or somewhere on the internet.
Hardwithstyle isn't that great if you ask me because it only features most mainstream tracks.
If you wish to keep up with the most recent releases try
http://www.hardtraxx.nl/forum/hardstyle-releases/Have fun listening and I hope you found this information usefull.