4.5 under cap? Since decimals don't matter, that just means 5 under cap.
We need a much larger sample size to look at. Here is my data from today:

As far as those screenshots go Kenzo, they were taken for a reason: because they saw something amazing.
The discussion in the first link forgets to mention skill level difference and seems to treat it all the same (as if synthing something 1 level above you will skill you up just as quickly as something 5 above you).
The other thing about both those discussions is that they swear by the 'moon/day/direction' meme, which we know never existed. That means that these people cannot be trusted to have taken down any data, as that data would have quickly changed their mind about moon/day/direction. You won't even find a consensus in that thread that any of the opinions they give there are true.
We aren't going to compare the data to what people say happened in retail or to random screenshots because neither of those are reliable. We're going to compare the data to what makes sense for a fun game. If you break 80% of your synths 4 levels away
in the long run, you bet that's a problem.
edit: I'm not saying there isn't or can't be a problem right now. I just don't think a few screenshots is going to help anyone. I'll record as much data as possible and we can discuss how reasonable it looks like in paper, and we can discuss how things feel more difficult because of the inability to increase difficulty, etc. We can have a discussion around the data. Nas hates when we 'solve' things, especially if they're 'wrong', so if the data shows something funky, you bet he's gonna ninja it.
If you feel like contributing, post here the following:
Your synth level:
The synth's cap:
Number of successful synths:
Number of HQs:
Number of failed synths:
Materials lost: (if you lose all the materials, you add "1" here. If you lost half you add ".5", etc)
The total number of synths is successful + failed. HQ and lost is just additional data on top of that.
So if you HQ a synth, you add 1 to success AND to HQ. If you fail a synth and lose 3 out of 4 materials, you add 1 to failed and .75 to materials lost. This way we know the % of materials you lose on average per synth.
Let's generate a ton of data from all level ranges. Please don't submit data only from successful or unsuccessful runs. If you sit down to craft for a while, save -all- the data in the format above. If our results are tainted then nas will ignore them. If they match what he's coded in and we say "it's really dumb" then it's more likely he'd change it.