Taking a quick look through some measurements posted at
reference-audio-analyzer.pro (Headphone Out port) I'd say it looks to be a very competent device:
- Flat frequency response out to nearly 19.5KHz
- Very low output impedance (1.1 Ohm)
- Pretty good output power (216mw @ 100 Ohm, 92mW at 300 Ohm)
- Distortion spikes below -105dB with 100 Ohm load, ~110dB at 300 Ohm
- Jitter distortion elements below -125dB (in Line-Out mode)
There seem to be no glaring faults or bad measurements to my eye (I'm definitely no expert), and with regards to whether you'd achieve better sound quality with a separate DAC/amp combo, I would have to say the answer is
no. Save that $ and experiment with different headphones to really hear any sound differences.
It's a solid card, I would stick with it.