Ok, maybe I was misled by your phrasing, but when you said 'bring or teach us', I thought that you were including all of us. My apologies.

No apologies needed, my wording was ambiguous and is now corrected, thanks.

You're welcome.

only some parts of assembly were rewritten in C, where it makes sense of doing so
other parts were just cleaned up

to work on any of those parts of the kernel you would still need to know assembly well

You are probably right; since I am not a kernel programmer by any stretch of the imagination, I would not know what was involved in the rewrite. However, it's good to know that code is getting cleaned up, nonetheless.

I'm running -current on all of my Slackware units. I've noticed a small speed improvement with 4.1.3.

Actually, for the record, while I don't mind if people on other distros vote and/or respond, I posted in Slackware exactly because I wanted to prefer Slackware users or to be more specific, a distro with no automated dependency resolving. What I mean to say is that it has been my experience that people who employ such along with huge repositories tend to be a bit more casual about installed software and updates. I wanted to prefer more thoughtful, deliberate users which I am biased to assume are in higher percentages in Slackware users. On the flip side rolling releases like Arch tend to be more minimalist, at least in terms of numbers of installed packages.

In any case one of the areas I'd hoped to get at least anecdotal data on was overall just how much of a leap is 4.x.x. So far it seems a small step from 3.x.x to 4.x.x, thanks to Didier and nivieru, especially Didier's link.

I thought there might be some general curiosity (and there is some) but my reasons for the poll/thread were mostly mercenary. I am currently running v14.0 32 bit with a custom 3.12.0 kernel on my main box and I'm expecting to do an immediate step-by-step upgrade when 14.2 is released. I had hoped to get a clue as to how much time I need to set aside since one of the first things I expect to do is make an appropriate custom kernel. Correct me if I'm mistaken but it seems "make oldconfig" shouldn't be inordinately complicated and/or tedious in the jump from 3.12.0 to whatever version 4.x.x is default on 14.2.

So thank you to all responding and I hope it holds some interest, however minor, for most.

That sounds like an intriguing, enjoyable process. You'll need to upgrade from 14.0 to 14.1, then upgrade 14.1 to 14.2. It might be easier to back up your data and do a clean install of 14.2 and then bring in your data. Just a suggestion; I'm not trying to tell you what to do. I'm really liking -current at the moment; I'm running it on one netbook, a laptop, and three desktops.
Slackware 14.2 is going to be amazing. :)

I think it'd be similar to any kernel jumping, what, 8-9 versions? There will be a substantial amount of changes over the course of that time, and it will take you a while to go through them all. Depending on how you do things, it may be easier to take Pat's latest config at the time and use that as a starting point. Then you can add and remove from a known good working config.

I wanted my notebook top have better battery use and generally to avoid the proprietary catalyst driver of AMD/ATI which I needed with a 3.7 Kernel to keep the graphic card of the PC quiet. Both worked. I am considering to downgrade from openSUSE's tumbleweed to leap 42.1 on the netbook, though.

I just found out yesterday that fancontrol/pwmconfig works with my HD3870. My GPU fan is now running at 1350rpm (vs 4000rpm max) and the temp is at 42C and quiet as can be :)

I love your response and choice of words ( "intriguing, enjoyable" ) :D It describes the process correctly in an ironic but also a bit tongue-in-cheek manner. While I do both prefer clean installs and sometimes have had to throw up my hands on upgrades and fall back to a clean install, I continue to do it because I've found I always learn a great deal in the process even though I may grow closer to bald from yanking hair :)

I have 14.1 on other boxes and current on one, exactly to see if my main box would benefit from those upgrades when weighed against any downsides. My main box, while all-around Desktop much of the time is also a Semi Pro DAW and can involve a LOT of work getting things "just right" after an upgrade. Your post has caused me to consider installing a parallel Slackware clean install so I can A/B easily insuring a smooth transition. Once it's up and smooth I can choose to attempt the intriguing :) Thank you.

You're welcome, enorbet. :)
A clean install will certainly be quicker than upgrading, however, I don't want to dissuade you from past practices. I also enjoy technical challenges and I will try out stuff just to see if I can do it. I'll be very curious to hear how it goes for you. I have three Slackware64-current desktops, a Slackware64-current laptop, and a Slackware-current netbook. I'll be moving my wife's units to 14.2 when it's released.