The main difference between ICO and STO is that ICO tokes are almost like cryptocurrency and STO tokens are more like "electronic" shares from stock exchange.
For me more important is idea nad team behind project than the type of platform.
I also read that STO is tokenized shares, but I have little idea how it all works at the fundraising and ICO stage, and most importantly, tokens are paid to the bounty hunters in this case or not? If so, then there will probably be different platforms, different forms of payment, in general, this is all new and again complicated and confusing. I still prefer the old ERC-20.