I am currently still tweaking, but I've been a little dissapointed.  I've not seen amazingly better stuff yet.  the reduction in ooze blobbing is worth the money though in my opinion.

I just bought such an E3D Hotend on ebay, and perhaps I´m going to put it into my SD2
Short question: What exactly are the benefits of it? Or are there any?
I found at least 10 threads of putting it into the machine...

Very unlikely you got a genuine E3d from eBay.  Maybe post some pictures and a link.

My first test cube was about .025mm to large.  I put the extrude width overrides back to zero to see what I have baseline.  now its about .25mm to small ..sigh.  Also, i forgot to reduce the print speed.

Also, why I'm replying,  I'm  now seeing the diagonal "moire" effect on the walls.  Some fixes say adjust the driver pots, but i wanted to make sure it wasn't something obvious I've screwed up in slic3r before i go messing with electricity.

My first test cube was about .025mm to large.  I put the extrude width overrides back to zero to see what I have baseline.  now its about .25mm to small ..sigh.  Also, i forgot to reduce the print speed.

Also, why I'm replying,  I'm  now seeing the diagonal "moire" effect on the walls.  Some fixes say adjust the driver pots, but i wanted to make sure it wasn't something obvious I've screwed up in slic3r before i go messing with electricity.

A couple of questions though.

Setting the extruder to 195 does not seem hot enough to extrude ABS.  The wheel just grinds the filament.  I found a page about installing e3d on solidoodle saying you would have to increase temps by 20-30 degrees because the solidoodle thermistor under measured. Those docs were really old apparently since they mentioned things like "this hotend will let you get to temperatures of 350c+"  On the E3D's docs it blatantly says that going over 295C would damage the thermistor.

I set things to 220 and ran a test cube successfully.  Bridging seems to be suffering though... What range should i be shooting for with the e3d v6? What about PLA?

Second:   The temp seems a little less stable than old hotend.  I probably need to run PID tuning again.  When i did it before the hotend had no plastic in it and i had the enclosure removed with the bed cold.

Third:  Are there any good profile management solutions for slic3r (or a different slicer)?   I'm having to keep a notebook of what profiles are for what.  It is going to be a big task converting everything to the new E3d.  I have a lot of manual pre- post job code.

note: I forgot to turn off HDR for first picture and didn't have time to retake, please ignore stitching issues around the stepper motor. I did not take a bat to it.

i found the kit here:
https://www.matterhackers.com/store/pri … -universal

I can get the fully assembled version from e3d shipped to US for about the same price (barring unexpected international fees.)

Also, since this looks roughly drug/bomb related, has anyone run into any problems importing this into US?

I replaced my jigsaw with the lawsy mk5.  Since i couldn't find a good concise  list of steps (in text at least...) on removing the old extruder assembly I'll try to give my blow by blow it case it helps someone in the future. I immediately printed another lawsy .. and ill probably print another one tonight.

0a.  i stared at the thing for a week (see above
0b.  i determined that there was little chance of saving the jigsaw assembly since the minimum number of required screws that needed to be removed pretty much makes it fall apart

1. I disconnected the hotend wires.  Note:  the quick disconnects have a lock of sorts on the red/blue end.  the actual piece that comes out is the tiny white side. pull on that little lever sticking out of the colored side while pulling on the white piece and it will come out really easy.

2.  I took off the 4 longer screws that attach the assembly to the stepper motor.  Note: the motor just sits on a perch behind the assembly so make sure you catch it and set it aside gently.

3.  i removed the 2 nuts visible from the front that attaches the assembly to the perch.  I noticed after the fact that the screws go all the way through the perch and can be steadied  with a Phillips head screwdriver (the blasphemy !! ) if the nuts just spin.

At this point you should have the entire assembly in your hands.  Now to remove the hot end.

4.  Remove the 2 nuts that hold the hot end onto the assembly (I now know why it took so long to ship the blasted solidoodles.  They must have had a crew of 20 who's sole job is going in with tweezers and pliers to attach these nuts to the captured screws.   incredibly frustrating. look for "solidoodle replacing hotends" for tips..)

5.  Now you have to deal with the piece of wood  around the hotend.  I suppose you could cut it with tinsnips or something, but like I said, I wanted a way back worst case scenario.  I decided to unscrew the peek insulator from the nozzle.  search for "unclogging solidoodle nozzle" for tips. I will add one thing.  slide the black insulation off and locate the thermocouple. it looks like a tiny glass bead attached to the nozzle with kapton.  if you have to use a wrench, steer clear of this. it is very fragile.  In hindsight, This is probably the most dangerous part of the operation. 

Now you have everything in pieces.   Pick up with the instructions for installing Lawsy's mk5 extruder on the thingiverse page.  I ended up reusing most of the screws from the old jigsaw.

I did have to improvise:
1x m3x10mm  - for the locking arm - used an old ugly pan screw that was way too big.  i cracked the top hole but got a good firm lock on the arm.  probably not the best approach

1x m3 x "shorter".  for the filament guide, you need much shorter screws than stock.  the left one i ended up chopping a bit off of one of the original hotend to wood screws with a dremel tool. for the right end i used one of the bolts from the tension arm assembly.

I was able to use the extra screws to put the jigsaw pieces back together ..just incase.

protip:  when cutting bolts, you will invariably screw up the threads (lol ..puns...:) ).  Put one or more nuts on the bolt before cutting it.  Once cut, removing the nuts you will mostly straighten out the threads.  Also it will be a lot easier to cross thread so be really careful. Also the nuts gives you a good place to grab it with a vice while your cutting it.