Hi Piotr Katzpersky,
Thanks for the demos.
Well, initially, I thought the first demo (the competitor) had the smoothest legato which caused me concern, but then I realised the second and third demos (the Synchron Strings) were rather louder, which would likely affect the transition from one note to the next.
Also, on further inspection I discovered that the first demo wasn't completely smooth either. It's faint, but I can tell when one note ends and another begins. This is also true for the Synchron Strings demos, but since they're louder it's more obvious, which is probably what led me to think the first demo was smoothest at first.
So in the end, it's difficult to judge.