Never happend to me. Saving project and parts should do.
I also don’t think OT is complicated. Complex, sure, but there is an underlying logic to how things work and thus OT feels like complete.
And when I have to look up how certain things work, because I have not used them in a while, just speaks for how many tasks the OT can do and how good it is at doing those imho.
Please don’t let potential users believe, a correctly saved state won’t stay as-is.
It*s not due the complexities in the machine that let it sound differently, but it’s the “think you saved it” (aka user error / for example not saving parts).
Parts and Sampling were tough for me to understand at first, everything else was super easy to grasp.
The fact that the volume knob only controls the headphone volume!
Everything else is fairly straightforward.
I am a “Save all parts” every 10 minutes and once more before saving the project kinda guy.
Never had the OT sound different than I expected (except for that silence when I didn’t move the cross fader off of a silent buffer)
It is possible to forget to save recording buffers and lose them when power cycling the machine. This, in my experience, is the main cause of the ‘it sounds different after turning it off/on’.
For me, one of the most complicated things about the machine is how many different things the trig keys can do; between trig modes, midi mode, modifier keys, scene buttons, record pages, and many other things besides I find that pressing a trig key does what I think it will only about 80% of the time. (:
And often if you accidentally change something, it will be too late to automatically undo it. The OT can be unforgiving, even if you account for the complexity.
Is this how you dress?
/joke
The ongoing battle is with clarity regarding scaling and units. There are a lot of little numbers that don’t come with an explanation in the manual of how they relate to the parameter they represent. Even when you do get a hint on the forum it’s a bit of a chore to keep straight when “12” is equal to so many beats or what interval it is when applied to the rate parameter.
Of course it does pay off, eventually. The OT will require you to confront more frustration than the digiboxes.
Oh, most complicated thing I did with OT was playing live while being tired + under influence.
You got to get your brain straight for operating this machine correctly!
Lesson learned once for all!!
Actually this is quite a relevant point, some parameters make sense in a 0to127 or -64 to +64 format, some show meaningful values (examples being slice number or comb filter note) but some parameters don’t make sense with arbitrary values and don’t have actual real world values shown, examples being eq or filter frequencies or compressor parameters.
It would sure be handy if there was at least a look up table in the manual.
Yeah you don’t want to be trippin’ when you Octatrackin’ 
Same here. I just had to practice, practice, practice.
Yes, once you adjust the recording buffer size, I think you have to restart. I’ve had this problem. So, I usually wait until I have everything saved to do this.
That’s because you changed Memory settings. “Normal”.
It actually only happend to me once or twice, but the feeling when you’re frantically trying to get your pattern back…oh noes… 
We have one layer of undo for copy/paste and clear operations (press button combo again), but that’s it - so save parts often as possible, save the project always after major changes, save the project when you’re taking a break, save the project when you’re content with the current state, save the project, save the project, save parts, save the project, save…
Btw, interesting to see that others also have the habit of saving twice^^ 
I usually save the project twice, save all parts and then save the project again before I switch of my OT (check cf card led for activity before turning off power, only switch off when no activity is indicated).
And I always give my OT a gentle scratch on the back before I walk away 
Didn’t know it was a known behavior! Good to know, thx Sezare.
In all seriousness this is one reason I bought the octatrack. I wanted something esoteric to wrap my head around. I wanted to spend hours studying, reading the manual, discussing, watching videos. I wanted a challenge with a good reward on the other side
Edit: at the same time I was learning Octa I was also learning boogie woogie piano and the contrast between the two was very fun…one absurdly heady and one brute force practice
Actually I even believe there’s a pop up telling you do 
Most complicated is a tough call.
-Knowing what exactly you are saving when you save. Parts? Patterns? Projects?
-Sampling settings.
-As said above, it took me quite a while to wrap my head around track recorders being completely detached from audio tracks. It’s one thing in theory, but in practice it’s hard to make sense of. Until it does, and then it’s really useful, it’s just a mental habit to overcome.
And seconding all those who say you have to practise and keep fresh with it. Don’t leave your OT untouched for more than a few weeks!
Nah, the pop up warns you that the buffers will be erased I think. I had nothing in my buffers, hence my surprise.