MTL (which is what I do) is fine. DTL is the one which produces vast amounts of water vapour. I saw a guy in a car in front of me the other day and every time he exhaled you couldnt see though his car anymore!!!
Thats the type which annoys me. Most of the time with MTL nobody even knows I am vaping.
A friends brother does the whole huge clouds of vape thing, and both myself and my friend have noticed it's gradually causing a residue of glycol (I think it is) to form on the windows etc at his house. Nowhere near as bad as the nicotine stains you get from smoking*, but still not something you want building up on your photos, windows, TV and monitor.
He's also set the smoke alarm of a few times, from another room with his vaping to give an idea of how much of a cloud is produced.
I'd much prefer people to vape than smoke, but not a fan of the raspberry steam train look myself.
*I've said for 20+ years that if you want to stop someone from starting to smoke, get them to spend time in a room where smokers sit and point out the stains, or even better, get them to clean up a smokers computer and point out that all went into, and out of the smokers lungs so if it's made that much of a mess of the computer...