It's time to upgrade from the FiiO K3

I finally have the money to upgrade my dac amp situation, which is the K3. It’s served me well, but I want something that will give me more inputs and that gives my music more clarity. I use fairly low impedance headphones: m1060c, tin T2, m570, and SHP9500. I just got a pair of DT 770 Pro 250 ohm as well. I want something with a super low noise floor and output impedance. I also want a neutral sound. I would rather keep my total spending on a dac amp under $500, but the Topping A30pro and D30pro seem like they might be worth spending more on. Right now the main two I’m looking at is the Apos ensembles for the A30pro/D30pro or the A50s/D50s. Which one is a better bang for buck? I honestly don’t want to have to upgrade again for at least 5+ years. I’m not saying I won’t pick up a tube amp or something for the DT 770 Pro and other stuff I get in the future, but I don’t want to upgrade the dac or solid state amp for a long time.

Basically is saving ~$160 usd on the A50s/D50s worth it? Is there a better solution that these two bang for buck wise? Again I’m coming from the FiiO K3 which is great for ~$100, but is gonna be shit stomped by almost any dedicated $300+ dac/amp solutions. What do you guys think?(Also I should probably wait for reviews for the 30pro series, if that’s the direction I choose to go in)