To be honest, the main disappointment was Spa itself, I spoke with them over the phone a couple of times and they have been quite rude to me.
About the crank itself, the quality was quite low, but so was the price, so no problem with that.
The real issue was that removing the inner chainring bolts caused the thread to strip off!
The bolts were extrenely tight, and something felt wrong when, after the first finally loosened, friction didn't decrease much, as if there was a very strong thread locker applied (which was not).
I called Spa to make sure they were happy with me going ahead and fully removing the bolts, even if I warned them I would probably end up stripping them, and they were. They told me some of those pre-assembled cranks are assembled with the bolts way too tight, and to just go ahead.
I did, and it was a murder. 5 out of 5 threads stripped. The alluminium of the body just came off together with the bolts.
I don't think they were just too tight, it's as if the bolts with the wrong thread pitch were screwed into the crank. It was a real shame seeing a new crank ruined like that...
Given it was so cheap, not to mention the only 160mm on the market, I thought to keep it just to try what a 160mm feels like, but then, to what avail? I wouldn't have been able to fit a new chainring. So, the chainset is on its way back.