I endeavoured when starting a new job last year to be totally digital - I use MS OneNote on a Surface Pro. The experience is very close to using a gel pen on paper for me. The handwriting recognition is remarkably good - I don't really write much but occasionally I'm searching for something and it finds my marginal notes. 20 years of almost exclusive keyboard writing has taken is toll on my already poor handwriting.

It's pretty close. The tactile sensation of writing against paper versus glass is different.

I do wish pencil could be attached to the ipad easily without having to buy a special case though as they always tend to separate in my household and having to go hunt the stylus down makes it a lot less useful.