FWIW, I have all 3. 610s, 900s, & 650s. The 610s are more lively than the 650s to my ears. That said, they're not as lively as other offerings out there. The 900s are crazy fun cans. And yes, the 610s are kind of like a dull version of the 900s. Lesser lows and highs in comparison. Still I think they are quite nice, especially if you can get them at a sale price. Maybe you should be comparing them to the Massdrop offerings instead if you're looking for a fun sounding pair in that price range? I'd offer to help but haven't gotten to hear any of them myself.