When I bought the RIG it cost $130. My question is would it be a good idea to buy something like HyperX Cloud or stay with the HD600? will the HD600 provide good experience in games?
Sorry, but I don't understand your logic here.
You have a $400 pair of headphones and your questions is what exactly? They're obviously going to be better than any kind of crappy "gaming" headset.
Do you really think the likes of Corsair, Kingston, SteelSeries etc. can compete in terms of audio quality with your Sennheisers?
"Gaming" headsets are largely a marketing thing and nothing more. Sure, there's the convenience of a built in mic, but they are otherwise in general just cheap headphones with a lot of branding and marketing slapped on them to appeal to "gamers".
I only have the headset I have because I didn't have to pay for it. I admit I used to have a cheap Plantronics headset before, but that was no more than $50 and the plastic broke on the end.
Been years since I had a pair of Sennheiser's, but I see no reason whatsoever that they wouldn't be good for gaming. I have used my Sony WH-1000MX2's for gaming earlier this year, as I got stuck in Sweden for a few months and they were just as good as my Corsair Virtuoso SE's, if not quite as comfortable due to the smaller ear cups.
Maybe I'm not picky enough, although that said, wireless headsets do have one advantage that I didn't really expect to like, but it turns out that cutting the cord is quite nice.