(Guesstimating) Better than smoking, but as any doctor will tell you, putting anything that isn't air into your lungs is worse than not putting anything that isn't air into your lungs.
I say this as someone who both smokes and vapes cannabis.
Man, I dunno about you, but as someone who vaped and smoked weed a couple years back, the vaping was way worse for me. I would get these weird phlegmy coughs that I never got from smoking. I think part of it is that vapes hits feel so weak, so I would end up just power dragging my hits, causing this effect. There were days where I swear my lungs actually felt like they hurt.
Stopped vaping and haven't had this issue since. Anecdotal, but there you go.