The Riptides are buttery, you can feel it when you take them out of the bag, they have a slippery yet dry feel to them, they're nicely molded, no ghetto plastic around the top and they're flexible like theeves/khiro not hard as fuck like indy/thunder/shortys, etc. but very different than anything else, they're very soft/squishy.
I've tried them in indy, theeve and thunder and if you are a truck nerd you can tell the difference straight away. YMMV.
I'd say they're worth it. Not sure if you need to worry about ordering truck specific ones tho, as they make ACE and Theeve cups, after about an hour I'd imaging they conform to the plate anyway.
Grosso can't be wrong, can he?