Looks like this deal is back for new users. I couldn't get the exisiting/expired user work around to work for me unfortunately, so looks like they've closed that loop hole.
Usual comments on the UI being dated etc but the audio quality is fantastic in MQA on HiFi plan (normally $23.99 a month).
"Get unlimited access to 60+ million tracks, 250,000+ HD videos and live events, completely ad-free. TIDAL members also get the chance to experience exclusive music and videos that can’t be streamed anywhere else."