I’m about a year and a half in to being a lite-audiophile. Although kinda new to this, I’ve owned Grado SR-60s for over 20 years and 80i’s for about 5. Last year when I took the plunge officially, I bought a FiiO X3 ii, Schiit Vali 2, Genelex Golden Lion 12ax7 and a pair of HIFIMAN HE-400i’s. Although I’m loving the HIFIMANs and don’t find myself dabbling with Grado’s too much anymore because of the piercing highs, I’m wonder what are the next must-have cans I should add to my collection. I keep seeing the popular AKG K7XX and Sennheiser HD-650s (HD-6XX on Massdrop) in my searches. Would one of those more so than the other be the way to go?