STOs have only just begun to arrive and are not fully developed yet as a crowd funding model because regulation is still being clarified in many regions for these types of offerings, however, any startup that has registered with the SEC and is using a compliant exchange to host its crowdsale and provides a detailed prospectus should be worth evaluating
I really don’t see STO seeing the light of the day for now, STO may be quite new which I agree, but they have still been around for some months now which virtually existing investor knows about them, but there has been little attention paid to them.
Look at when IEO first came out, it really dint take IEO more than a week to get all the hype and support needed from every angle, but STO cam virtually the same time IEO came too but still look at their development stage, very slow and I am sure it is because it indirectly involved government and the offer is quite too low for any investor to make money through it.