Yes, I've got a howies snowboarding jacket.
AFAIK it's a very densely woven cotten which stops a lot of wind. When it gets wet the fibres swell (absorbing water) and it sheds much more water and becomes even more waterproof.
IME (snowboarding) it makes the jacket stiff and wet which was less comfortable (not a major thing) but was also cold (I'm not one for being bothered by the cold usually). This is a major flaw as far as I'm concerned. Sitting on a windy lift in a wet jacket getting colder and colder is no fun. I'll be replacing it before I go again.
I suspect it'd be a similar to riding a bike in the rain i.e. lots of airflow creating a windchill effect with the wet fabric. It also holds water for quite a while which also makes it heavier. I suspect it's also going to be heavier and bulkier than equivalent synthetic fabrics commonly used for riding jackets. Whether and how much that might be a pain is up to you, personally I wouldn't.
So in summary, wouldn't bother. Using ventile for a biking jacket seems like a crap idea, IMO. If you were only ever going to use it as a windproof then maybe, just. But given we live in the UK a solely windproof jacket is getting close to the mythical chocolate fireguard.
I still wear my boarding jacket as I like it. But as a piece of kit to be worn in the hills it's pretty crap. In hindsight my curiousity about ventile landed me woth something that seems to be fashion over function (oh aye, I know it's Howies 😉 at least it wasn't full price!