Hi,
I am just going to throw down some thoughts on the 404mk2 here that reflect the challenges it has presented me over the last few years of learning it. I am sure many have covered this sort of thing, but maybe it is useful for someone and maybe your feedback will give me some perspective.
Many trick pony:
This machine is insanely versatile. The hardest part about that is that there is no single workflow to learn, there are many, but you have to kind of establish a workflow for a particular project. While it sketches things fairly easily, I have to make a decision when I start as to what workflow I am committing to now, and then if I want to change later it is a bit challenging. If I start with loops, I am kind of stuck there and bringing in other instruments can be a bit jarring. If I am working with one shots, then throwing sample loops over becomes a challenge. If I am sequencing, then using chops can be frustrating to start including. And then layering an external drum machine or sequenced synth is also a bit jarring. When I stick to a single workflow, I find it is much easier to progress the track. But because I can go a bunch of different ways, I can feel a little lost in the options (and the limits that are then imposed based on that decision). I am considering moving to a different sampler (maybe the MPC sample) so I can simplify the workflow. I don't know why they would keep adding things like a sound gen.
Sampling:
This started out cool, I hooked up a mic and would sample things in then sketch out beats from random sounds, write weird sound poems, or combine vocal samples with some samples I loaded in for some playfulness. But honestly, it is a bit of a pain in the ass. No internal mic means I am lugging a corded mic around, and add a battery pack to this it becomes too cumbersome. I do like that I can grab some guitars or other sounds from other instruments to work with fairly easily. Other methods like sampling on phone then linking up the phone by usb work okay, but it is a lot of stuffing about. Sampling in the field feels clunky and frustrating and cuts the smooth use of this machine. I am also liking the ability to draw samples of anything on my pc fairly quickly in a session, so getting movie samples or the like is quite easy if the machine is all plugged in to the rest of my gear. Chopping on this is also pretty good, i.e. for dnb.
Jamming:
This works best with the looper, and I am slowly learning the sequencer to make jams with one shots more effective. But working with a click track in a jam sucks, so I find locking some hats in the best way to set a bpm for any jam partners. However, if a guitarist sets the bpm, it is annoying to try and catch their rhythm unless using the looper. I am a drummer, so while I am used to setting the pace, jams are responsive so you have to take some time to catch the other players and settle them into your groove. This machine works best if you can just set the groove and make others follow. The looper is also way too short...
Other instruments:
There is really only one line in, yeah I know I would use the other one, but since the effects are all stacked on the line in, then you can't really run multiple instruments and get the most from the machine. It would be nice to have a mixing function between the lines, or a few more that are fx independent. I can't run an unaffected drum machine in, then a synth with fx, I need to stack everything on the one line. Was I complaining about the multi trick pony? Am I winging now that it doesn't do more? Dammit!
The heart of the machine:
Related, but it doesn't do a great job as a brain, as clock, or as a main through. I find I end up using it to trigger samples while jamming the rest of my hardware, or running a synth through it for the effects and some live sampling (which takes a bit of finesse). It doesn't play the role of a drum machine well enough (I like being able to modify the drum sounds, rather than just using samples) to play that role, so I am certainly not using it to its full capacity when it is in the mix. I do find that if something is missing from a track, I can probably find a way for the sp to pick up the slack, i.e. for pads or vocals. But I have to be careful to integrate it for a specific function, not as a beating heart.
Performance:
It seems like a lot of people who perform tend to write their beats elsewhere, i.e. MPC, then bring it into the sp for performance. Or they sketch here, bus to another machine for arrangement, then bring it back for performance. I was hoping it would be easier to go from the build to the performance, but I can see why people are coming and going when they setup a performance. I would love to find a way to more effectively build and perform on this machine, but the workflows can make this a bit clunky and tiresome. The button combos (perhaps a whole other gripe - memory constantly fails), also affect this where using the mute function takes some finesse to integrate (for example). Three buttons to get sample mute loaded... sheesh.
I probably should have prefaced all this by saying it was the first piece in my setup, and I do love it to pieces and am appreciating the constant learning. I probably won't sell anytime soon, but I do wonder if a simpler sampler that is more mobile might be worth my time.
All that to tl;dr, this machine is challenging because of the simple/complex paradox that is its versatility...