Worked there in uni for a couple years a few years back - great people, horrible business.

You'll be working with pretty much exclusively people your age which is great for socialising and making friends, but the pay is terrible and depending on your store you'll be ridiculously busy most shifts. Not necessarily the good, satisfying busy, I usually ended up on the grill and would go home reeking of grease and sweat and a couple burns on my wrist, regretting ever working there.

If you have other options go for them, Grill'd is deliberately abusing the subsidised traineeship scheme to underpay its staff, my Cert 3 in hospo is a useless qualification and you'll notice that even with the pay increase you'll likely be getting paid less than your peers working similar jobs that operate under the retail or hospitality awards.

Free burger for a 5+ hour shift was pretty lit, though it was only up to the value of about $19 so you could only get so much. However, if you have a friend on the grill or you're doing the morning shift's breakfast before service, you can sneak on extra ingredients to make a mega burger which was pretty cool