I have three stylus devices. Galaxy Note8 phone, a Galaxy Note tablet, and my main laptop is an older Acer Aspire R572 convertible that runs a stylus if needed.
I use the stylus all the time on the phone and the tablet and less so on the laptop for day to day work but do use it occasionally. Many laptops now come about default with touch on the screen but that doesnt necessarily mean the stylus will do everything someone would want it to depending on what they are looking for. I very rarely use the touch screen (fingers)
I do a good bit of digital drawing and sketching on occasion so having a laptop that allows for many levels of pressure sensitivity is important for that but less so if your just wanting to be able to markup/annotate drawings or have customer be able to sign contracts/invoices digitally which is nice for paperless.
For using the laptop in the field with the stylus it would seem essential to me for the laptop to be a convertible model where the screen can fold over flat and you can use it like a tablet or have a detachable screen. Using the stylus on a laptop in its typical configuration wouldnt be effective for me and I'd be opting for a Wacom type tablet if I needed it but thats not too portable.
If your just thinking about marking up drawings any touch/pen enabled screen would be fine.
I tend to take my phone and laptop everywhere and take the tablet when needed. I use the phone and the stylus for most small field notes, lists, and so on (multiple times daily). For measured takeoffs I tend to use the laptop in the field in conventional or stylus mode. And for small jobs I may take the tablet, snap a photo, and annotate notes and dimensions with the stylus right on the photo. They all save/sync to cloud storage so this keeps me pretty much 100% paperless and I have all my documents on every device no matter where I am.
I would agree with the advice with regards to a CAD program that is resource heavy on the video card side that would trump the stylus for me. I have never had a problem running any of our software, doing 3D photorealistic rendering with tons of high quality textures, and so on, but Im also not typically working with massive models (an entire home or floor of a commercial building may be it).