You missed telling important details affecting to what features are needed for sound card to be optimal.
Like are you going to use some speakers (analog or even digitally connected) or headphones?
And as tip you might want reconsider that playing with font size as it makes reading harder and hence in long term moderators might not like it much.
("Use BB Code Editor" button above right edge of message text field shows tags and "Remove Formatting" strips them all)
But first of all PCI is completely obsolete bus, which should have disappeared from most motherboards for leaving space for sense making positioning of PCI-express slots:
All higher end graphics cards physically consume space of slot position below that main PCI-e x16 slot...
And especially with non-reference heatsink models you'll want to have "breathing space" between graphics card and next card below it.
Same heating problem for slot above main PCI-e x16 slot, with also increased risk of EMI because of short distance.
So hopefully most motherboard will soon have only PCI-express slots.
So from those PCI-e variant DGX is only sense making.
I mean why would you buy something which you might not be able to use at all in next PC when same price level more future proof part is available?
And if PCI-e card fits physically to slot correctly (=without violence) it works electrically.
So you can put it into your motherboard's lowermost "big" x16 PCI-e slot (which is actually electrically x4 slot) leaving lots of cooling space between it and graphics card lowering also risk of interference.
And then to features part:
Realtek ALC1150 of that motherboard is quite capable "codec" chip, so assuming implementation is good and it avoids EMI problems separate sound card might not offer any advantage.
In fact ALC1150 chip's digital to analog signal conversion quality is "step" better than that of budget price sound cards.
Though that particular thing likely
isn't that noticeable for accuracy of human hearing.
So unless that integrated suffers from interferance like (static) background noise and short duration/transient noises in its output that price level sound card can fail to give anything better.
But if you're using headphones integrated Realteks lack feature which can be major boost to gaming immersion: Binaural sound.
Binaural sound mimics how human hears in 3D with just two ears/"receivers" directly in signal.
And despite of lots of Xonar hype and even more bigger/hypefull Dolby Headphone name that's unfortunately rather mediocre.
Instead of purer binaural-simulation trying to mimic surround sound on headphones it was designed to mimic room acoustics aka echoes of old movies theaters.
Creative's cards have lot less echoing binaural-simulation making them better for headphone gaming.
Their drivers aren't nowadays any worser than in any other product and while product range has had its facepalm moments there's now good range of sound cards from budget price to "luxury"price.
