Though the new skill system offers a great deal of variation, the implementation could be a lot better.
Currently talking about the dex based systems, though similar can be said overall for the other combat classes.
Aside from the ath/defence malii (get to that later), one of the main problems is the relative stats increases with skilling.
Currently we have massive skill effects on imps, with very small changes in any of the main weapons stats. This gives us two issues.
Firstly it makes the current defensive imps near useless, secondly, minimal removal of combat skills will gain huge increases in skills such as agl (though it does give a prospect in light of the 'loss' of such skills like poke and hack for people to take different secondary skills like repair, recycle or vehicle use).
As shown here, the dmg/skilling line is probably ideal in it's curve (not a fan of soft caps), the problem is it's gradient, it's too flat.
Increasing the gradient and fixing the defence imps but leaving the large offence effects would sort it, but again there would be too much freedom within other skills.
Next problem, variation within a weapon choice.
Currently the offence imps are either mainskill increasing or main and subskill increasing.
What this leads to is less a choice about how you want to play your weapon of choice, and more of what weapon will you end up with a cirtain number of defencive imps.
What I'd suggest is a something more akin to the NC1/2 system where you have mainskill imps like the SA/SF/etc with smaller subskill affects, this lets you choose your weapon. Then imps with higher subskill effects but no mainstat ones. This means you have options about where to take your setup, more defence, or more offence (the classic target3 or ppr/moveon choice for judge users back in late NC1 for example).
It would lead to a lower weapon range, but given the wealth of new weapons (and new ones to come) and the fact this would enhance class distinction, a small price, and one I think should be payed.
Again, I think PA should be classed as an offence imp. Small defence gains, with an offence benefit. Then the PJs would be the opposite, no offence gains and larger defence benefits.
Lastly, the defence/ath nerfs.
It appears to me that KK seems to be making (or at least leaning in the direction of making)imps almost 'skill neutral', no overall benefit, not something I'd be enclined to agree with. Implants are a risk, they are expensive, they get damaged etc. general maintenance is required. This should not be penalised by offering people no benefit over not using them at all.
It also does not offer a clear enough message about what an imp is really for (though I will be one to admit that the complexity of NC's skill system is something I like a lot) and adds frustration if anything.
So again similar to the NC1/2 items, defence imps should remain defence imps and offence imps offence imps.