Bluesound Node 2i or iPhone as an endpoint?

Im thinking of buying a headphone Amp which has an integrated dac. If I have Roon, are there any advantages of using Bluesound Node 2i over a cheap iPhone/iPod touch connected via the camera USB port to my dac?

The only downside is that if I use my my phone it will tester my iPhone to the dac. But £500 for the Bluesound 2i seems a lot of money if I’m not using it to its max capability?

I hope this makes sense. im still very much a noob audiphile and learning as I go along.

Have you considered a raspberry pi plus an output card or you could use it’s USB to headphone amp DAC. So much cheaper and will likely sound as good.

I do need to look into raspberry pi’s as Ive heard so many good things about them (creating arcade emulator boxes etc). Its something I would have been all over whilst at university but I find I have less time nowadays for tinkering,

When I look to get a hifi, im likely to go for an all-in-one system like the Naim uniti Atom for the same reason.

iPhone obviously useful because you could use it as a roon controller. I use an iPhone 6S with an Oppo portable headphone amp and it works well.

I have the Node 2i. I don’t notice much if any difference in sound quality between the Node 2i and my iPhone 7 tethered to the amp via USB. But then, my Peachtree Nova amp does handle the iPhone particularly well (via USB-A with “Dynec”). I don’t know if your DAC/amp would isolate your music system as well from iOS device noise.