I don't own any MCusta. So this is purely just an opinion for the sake of discussion.
I have seen MCusta knives and know that they can make good knives. What they lack I think is user-feedback. Many knifemakers have made a lot of back lock knives, and thus many Japanese knife users have a good amount of experience with it. However, when liner/frame lock knives started to swarm the global knife world, the Japanese knife law got tightened up (in late 90'/early 00'), due to several crimes involving knives. We cannot really carry any knives fully legally or comfortably here and therefore have not really built up our experience on these types of knives. Also, MCusta and G Sakai are probably the only mass production knifemakers making these types of knives in Japan.
This makes, I think, MCusta devoid of user-feedback on the modern lock mechanisms (including lockbar tension, % engagement, detent strength, etc) for improving their products.
Although MCusta seems to be a typical Japanese company lacking international affairs, you can probably send your feedback to them. I am sure they can understand it in this Google Translate era!
Miso