honestly just depends on what kind of experience you want currently.QSP or HTML version?
QSP is more complete, HTML is the one still being updated.
they both have bugs of course --the HTML version has more right now due to Snekk still figuring out Twine, the QSP version has a couple major problems that are a major contributing factor for the switch to Twine-- so it's more a pick your poison kinda deal?
playing the QSP would probably be a good way to get a basic feel for the game, since it's the earlier version, the HTML version is kind of barebones since it doesn't have all the QSP content in yet.
I personally enjoy them both tho.