Total delusion :(
the pros:
• can store three separate presets, each with different preset tempo.
note that if you switch between these in mid-song, you would have to tap in the tempo anew, as the presets will store their own individual tempo settings.
• some nice sounds (I like the sweep delay, very cool for psychedelic stuff; the backwards sound does what it should) so you can mess around with it in the house
and that's about it.
Now (ahem) for the cons:
• a lot of unusable sounds (i do a lot of weird experimental stuff, but even for me some of the settings are pretty useless e.g. the glitch one)
• very fiddly, the alt button is tiny, impossible to use on the fly (basically each button and knob does more than one thing, which is always a nightmare)
• does NOT like other power supplies. i used my trusted power supply which works with all my other many many pedals ( including much more expensive and complicated ones) without any problems; but with it, this one froze several times ( I had to disconnect and reconnect; I thought the item was defective, but realised it is simply the fact that it absolutely must use its own dedicated power supply)
• the "hidden" reverbs: firstly, why on earth are they "hidden"? You can only use them if you have the "chat card" constantly on hand unless you can remember every setting, every separate parameter function etc etc.. Secondly none of the reverb sounds are particularly good in my opinion. Thirdly tweaking them is really (once again) a pain, as you have to use the same knobs which are used to manipulate other parameters - you need to press and hold down a tiny button (that "alt" one) and simultaneously tweak them - again useless in any kind of live setting. If your hand slips, you end up tweaking the delay time or other delay parameters, messing everything up. The reverbs are only usable if you spend a lot of time experimenting, and then saving as one of the presets (note that this means saving them with specifc delay settings too; again, if you change from one preset to another you lose the previous reverb setting.)
• using an expression pedal (for me a key feature of any delay pedal) is not good with this. I have a few Nektar expression pedals which i use with other pedals (Earthquaker Devices, Roland/Boss) and have absolutely no problems with them, thery intereact well, they do everything they should (and they are cheap but look cool!). But with the Line 6, it's really bad. Also assigning everything is a pain again - all too complicated and (again) impossible on the fly.
• Finally the looper is USELESS as it has no erase function!!!!! Neither for the last recorded overdub e.g. if you loop, record over it, say 4 times, do a fifth overdub and decide to remove that one, you cannot; and then when you want to erase the whole thing at the end- you cannot!!!! How absurd! I honestly (again) thought the unit I had was defective, but then i downloaded the manual and discovered no, that is how it is designed and built - there is NO way to erase everything expect by pulling the plug and restarting. Forums will tell you simply to "record a blank track" to "erase" the currently stored one i.e. keep the record button on while not playing - for at least the exact amount of time as the total previously recorded loop. How on earth can you do that live?! This is a SERIOUS design flaw.
So basically I was totally deluded with it and was actually going to return it, genuinely believing I had received a defective unit. Having realised that it isn't, it is just an inherently bad design, I am probably still going to keep it to use just to have three separate preset sounds, and nothing else.
I find it incomprehensible that this thing gets such good reviews. (now those people can give me a thumbs down....)
BTW I repeatedly wrote to the EU suppliers (Yamaha music) in order to check whether these really are inherent design flaws, and it was not simply my own unit at fault, and they simply ignored me (so not a good company to deal with, clearly they don't care about the people who pay good money for their products).
Thanks to Thomann as always for doing return request and clarifying everything about that side of things.