I was thinking to start such discussion, happy to see somebody started it already.
The system should involve to the old version: +11/12 safe, and just 1 downgrade if the process fails with HD ores (when I checked the Cash Shop joining this server I *seems to* remember HD ores - if somebody can, please, confirm or correct me - said "in case of fail your gear will be downgraded by 1 refine without break").
As padkoto said already the actual change makes no sense: people will aim just to +9 (or even less) and most of bonuses from RE cards and gears will be "wasted"/unused.
I would also add, relating to this:
the 100% chance from +10 to +11 and +11 to +12 was removed because of long term worries.
... that is common to get worried, but that should be part of the process before taking such decisions (and not after). Testing is important - and necessary - to solve such situations, removing the chance to encounter them once in game. I wonder how many over +15 (or even +20) is around actually. Also give a short part of LeikaRO community a great advantage over others, cause of their over-refined gears before system change, is not really good. I think what players are aiming mostly is equality to each other, same chances: stating a system already released is not balanced and correcting it after fews players got *unfairly* an advantage is even more dangerous than long term worries. +20 items should be part of the game, without worries: it's more reasonable to adjust and nerf some skill or game mechanic in case such over-refines allows ridicolously high damages than deny people to aim to best gears to PvP/GvG with (cause actually refine system does this).
Last note: this system don't promotes donating for HD ores that, I think, could be a great money-making way to feed server bills, granting a long life span and allowing good performances cause is possible to rent better machines to host in.
Thanks for reading and sorry for my poor english, hope can be understood clearly.