The Akai S20 was the first sampler that I had bought. I had played with a myriad of samplers that belonged to various friends before this - some were even borrowed and in my studio for a time, but I never had owned a sampler of my own until I bought the S20.
The S20 is a decent sounding 12 bit sampler with very limited sample editing capabilities. There are no filters, envelopes, LFO's, etc, etc. There is only start time, end time, loop points, and various MIDI and button assignment functions. I actually like how basic it is. It keeps me from spending hours of time over-analyzing the sound...
During the late 90's when I used this a LOT, I mostly used it to sample analog sounds around the studio (mostly drum sounds) and then sequence these using my Ensoniq ESQ-1. (the S20 does have a built in sequencer but it is only 1 track with no obvious quantization)
My unit has updated memory so it can store a whopping 5 minutes mono (yes! count them... FIVE!!!) or 2.5 minutes in stereo. This then could be stored in memory but was lost once power was off unless you backed this to disk. The main drawback to this unit is it only uses floppy disks for memory.
Though I have other samplers now ( like my sampling software on my computer or iPad, or like my Emulator 4XT), I still find myself using this sampler from time to time - mostly because of its portability and no-nonsense architecture. Recently, I used it live at a show with my Arturia Minibrute. It was MIDI'd to the Minibrute, then the output was ran into the external input of the Minibrute. The memory of the S20 was loaded with various waveforms at different octaves - sometimes just a simple saw or analog waveform to thicken up the Minibrute, sometimes string sounds or sine waves at different octaves so I can add various overtones to the Minibrute. This has brought a new purpose to this old piece of equipment.