OK I have one and I’ll be very honest!
Difficult. If you fall asleep lying on your back it’s not such a problem, but sleeping on your side or stomach with the mask is really difficult, especially in the beginning. It’s also annoying when the weather is hot, with sweat that smells and irritates your skin.
Yes, it probably depends on the people. I wasn’t really glad with results, the flashing light just transforms itself in your dreams and it becomes very difficult to recognize it as a dream sign. I mean, the red light can become a blue hat or something, not really helpful 
I’m quite convinced you can get the same - or even better - results if you use your own dreamsigns, the Novadreamer needs discipline too so it doesn’t really “give” you LDs without working on it.
I don’t know about a newer version but I wouldn’t count on it - it seems Lucidity Institute has not been very active in the last few years. 
However there is someone working on a similar and cheaper alternative:
https://community.ld4all.com/t/new-cheap-dream-goggle-device/7863
Maybe you could contact him about the evolution of his project, it looks like he has a REAL alternative with great features, not just a building scheme or some poor goggles without REM-detection. AND he’s a member of our board contrary to LaBerge. (And he doesn’t pay me for saying this 
)
Don’t have a dream speaker, so I can’t tell.