I have been using the Octatrack for several years now solely for live looping + field recording playback (no sequencing or typical drum sampler stuff). It is a fantastic live tool for this purpose although it took me a bit to find my footing with it.
my set up would typically be:
tracks 1-4 would be armed with pickup machines (the live looper function of the octatrack)
tracks 5-6 would be loaded with flex machines pointed to the same buffers as tracks 2+3 (flex machine plays back samples from RAM and has the most flexibility for sample manipulation - playback speed, directions, slices, etc)
tracks 7-8 would be loaded with static machines playing back field recordings (static machines let you playback loooong samples from the CF card so they don’t take up any of the RAM you use for other sampling functions)
Octatrack lets you set up your outputs in a flexible fashion. I would use the main outputs to go out to my mixer and use the cue outputs to go into my modular for processing. each track lets you control your main vol and cue vol separately so I could use the cue as a kind of effects send.
the Octatrack also has three internal LFOs for each channel that can be mapped to pretty much any function. This is really handy for things like creating gradual movement in a track (assigning a slow LFO to pan a channel, sweep a filter or bring the track volume up + down)
I could go on and on…
you can see some of the things I talked about in action in this video that Datachoir shot of me playing around in my studio last year
so all that being said… I picked up an ER-301 late last year as an attempt to replace the octatrack. I liked the idea of there being similar functions but contained in a modular environment. one huge thing I miss is the stereo tracks. with the er-301 if you want to do anything stereo you have to use up two channels… so you start using up channels pretty quickly (BUT! you can have multiple stereo samplers/players on the same channel so there are ways to work around those stereo limitations). I also miss the effects section of the octatrack. while the effects struck me as being kind of lame when I first got it, I sat down and really spent some time finding the best way of using them to fit my needs. you get two effects slots per track with the octatrack. Between the 3xLFOs per track + 2xEffects, it saved me a lot of pedal + modular space on some basic effects/utilities.
anyway, that’s just my two cents on the octatrack as a live sampling/field recording performance environment.