I own the 325x and use with a Zen DAC V2. I’d always wondered what the ‘Grado sound’ was like, and to my ears is not significantly different to, or better than, all the different pairs I’ve owned over the past 35 years. This includes brands like Sennheiser, AKG, Audio Technica, Sony. I’ve tried Spotify, Tidal (CD quality) and hi-res and am underwhelmed. I do like the fact they are open back as it means I can still hear external sounds, like the postman knocking at the door, but I was expecting some sort of ethereal Grado experience, based on comments I’d read over the years, and for me that is certainly not the case.
Also the QA is pretty terrible, particularly regarding the cable twisting and headband finishing. The ‘made in America’ thing is certainly nothing to brag about.
They are also not particularly comfortable out of the box either as the stock pads are quite scratchy. You get used to them over a few weeks, and I also bent the headband to reduce the clamping force.
I’m one who doesn’t agree with buying lots of different items and returning them due to environmental implications, so am prepared to live with my choices, but I wouldn’t recommend either. To me a £100 pair connected to my phone with the supplied dongle DAC are arguably just as good, but you may feel differently.
To put it into context I recently bought a pair of Soundcore (Anker brand) Life Q30 for commuting (noise cancelling) for £56 (Black Friday) based on reviews I’d seen, and despite being Bluetooth, for not far off 1/10 of the price, and once EQ’d, I’d argue are not far off the sound of the Grado and Zen combination. People who suggest ‘night and day’ differences with external DACs are delusional in my opinion. Night and day is going from VHS to 4K.
I’d probably suggest you also consider the Hifiman Sundara, regarded by many as the best circa £300.