I ever use nanosim , powermill , hsim , aditspice ..
for analog design fast spice ..evercad aditspice is more accuracy (not detail setting )
but each fast-spice can run accuracy , nanosim even powermill can run spice like mode .will more accuracy but will very slow .and some tool need setting many many item . for analog designer , I just want speed up my simulation time .
hsim is for memory sim is very good (use 2 pass , first reduce some circuit) , other fast-spice also do partition circuit for speed up simulation time .
but nanosim is poor tool for me ..
by the way , cadence also have ultrasim fast-spice
magama have finssimPro