Amit BL :
Tempered glass is cool but cosmetics is secondary, I want the best performance a case has to offer.
Air 540 is cool looking and good, how is the S340 elite? better?
Best performance a case has to offer... What do you mean by performance? Ability to fit water cooling components? Air cooling? Hard drive cooling? Silence?
I only commented based on you asking about the 570x. It's expensive, and kinda bad for how much it costs. The most similar options would be the InWin 303, Riotoro Prism, Anidees Crystal AI, and the NZXT S340 Elite. Most of the other tempered glass offerings haven't been nearly as good. Well, even the Riotoro and the InWin have problems. Serious problems.
Honestly, you can't go wrong with any of the cases mentioned so far. It's probably more important to decide how you're going to populate the fan slots, and how you balance and tune the fan speeds more than the case design. Especially with cases like the air 540 or the S340 or the P400 or the 400C/600C that are compartmentalized, airflow is pretty much a non-issue as long as you use all the fan slots and tune the fan speeds appropriately. Thermalfake and Zalman though, I'd be cautious with their stuff.
I'd be more worried about which fans to choose when it comes to performance. For cases, I look for aesthetics and layout.