I am confused - are you saying that you got that particular Corsair memory to work in a newer (-103) NUC after it has not worked in older (-102) NUC? Normally if there is a memory compatibility issue (such as "density" or the lower voltage not being properly included in JEDEC SPD), a NUC revision won't improve that. It is true that compatible memory may operate slightly faster in newer NUC, but I'd be surprised if newer NUC actually changed compatibility. In this thread, the original poster was correct (saying the issue was not 1066 vs 1333 vs 1600 but rather the particular memory module) and allen_intel left out important information (he didn't explain that 1333 and 1600 are supported as 1066). The bottom line is that memory compatibility with current NUC models is very confusing because memory vendors often don't describe memory chip "density" which is important to NUC.
Although I agree that it would be nice for NUC name to have 30 vs 20, I'd be surprised if it changes this compatibility issue. When you read about 1333, it is not enough information to specify compatibility (you still need typically newer modules with specific "density" requirements, and of course the 1.35v).