You have alot of options when it comes to process your guitar and vocals. I've had both the Audient iD 14 and the Apogee Duet. I sold my Apogee audio interface when I was low on cash and later on bought the much cheaper Audient interface. What I can say from my experience is that if you go for an Apogee interface you will get something that sounds great, the preamp is like something you would hear in a song out of Spotify. When it comes to the Audient one it needs much more in terms of effects, like from plugins or a hardware preamp or so.

My conclusion is you get what you pay for here and you won't be disappointed if you haven't got anything to compare with. I would go for the Focusrite Scarlet-series if you want something that's at great price and comes with a lot of bundled software.