I love using vintage glass, there is nothing quite like being able to manually focus a great shot! They tend to feel well made, and to coin a poor phrase; 'look legit'. In all seriousness, they look fantastic.
I love the look of photographs taken using vintage glass onto digital, it has a softer, more unique look to a lot of modern glass. This can lend itself to some great results portrait-wise, and give a retro-contemporary film to your shots.
I tend to adapt full frame 35mm lens to APSC digital sensor cameras (such as the Fujifilm X-T2). This means there is about 1.5 crop factor when it comes to using the full frame vintage glass. So my Zuiko 40mm F2 is more like 60mm, and the Zuiko 28mm F2 is more like 42mm, etc. This means the lens can give you different results depending on what sensor size the camera uses. I find this can yield interesting results.
I find the cheap adaptor I have a bit bulky, but useable and well built. I have 3, all of which adapt different brand lenses to my Fujifilm FX camera. When I had the X-T1, I would use older glass all the time when out with family or friends. I have only recently started using the vintage glass on my X-T2 in recent videos, and have come to really enjoy it.
Keep your eyes peeled on my youtube page for more vintage Zuiko OM glass adapted to Fujifilm cameras! - Sly