SP2016 Reverb’s six algorithms comprise the Room, Stereo Room and High-Density Plate of the original SP2016, and the ‘Modern’ versions of the same from 2016 Reverb.
Room and Stereo Room differ in that Room has a mono input and Stereo Room is, well, fully stereo. Which to choose will depend on the nature of your source signal and/or the space you want to place it in.
Plate emulates a heavy plate reverb (absolutely beautiful on drums and percussion). The Vintage version has no Position, Diffusion or EQ parameters.
The sonic differences between the Modern and Vintage algorithms are significant, with the former working at a higher bit-depth, and being noticeably brighter and more diffuse. The algorithms themselves have no bearing on the value ranges of the reverb parameters, so you can set the Predelay and Decay times and flick between algorithms to see which works best for the job at hand.