Interesting question. As you said, it's really quite new... but has huge potential. I would imagine that early stage investors will love it because it has the potential to give them partial (or even full) liquidity while still letting the remainder of their investment ride.
Later stage investors, not so much because (a) they will typically want to hold out for higher returns, and (b) it competes with them. But I can't quite think of a reason why an investor would discourage an offering out of course.
I'm sure some clever people will figure out how to get the filing and reporting costs way down, making it a source of capital to even smaller companies. Very exciting space to watch!!