Just in case anyone else needs it, this is how I am going to do my install tomorrow.

Freddy,
  Good luck putting the M.2 in see if you can make a vid of the boot time.
Sounds like a really good system.
Carl2

It worked 

A bit of flaffing around removing other SSD leads for the install. Got 10 installed and to the desktop fine following that video. Took about 30-45 minutes.

Straight away it is noticeably faster. Breezed through screens in Chrome.

I'm installing drivers and things atm, I'll do a benchmark later and see what the boot time is for Carl.

I had set up defaults in my BIOS temporarily and I ran the benchmark thing. The results were very nice.

Then I set up my overclocking again and it's shot right up. SSD is number 2 - just look at those speeds 

According to them I have a UFO here 

http://www.userbenchmark.com/UserRun/490643

Carl, Task Manager reports boot time was 14 seconds, which is about what it felt like.

1,493 MB/s  mighty impressive, my Samsung EVO is about 450 MB/s, so according to this benchmark it is at least 3 times quicker        

Keep that BCLK at 100 Freddy, just in case 

Yes it's at 100 - I set it up the same way as before 

The new SSD is noticeably faster on things like installing and unzipping. I'm getting quick at these installs now. The bit I don't like is connecting the chassis fan lead when I put the sides back on - it's very fiddly

  I had to check my speed first is the old gateway,  into win 8 and I'm not sure how much different OS's load, 24 sec.  I had to try the HP next and I have trouble believing it myself, 10 sec into win 10.
I did this timing it on a digital watch, not sure how it was done using task manager.  So I feeling there is something wrong here.
Carl2

I don't think there is anything wrong really, you still have to wait for BIOS to load. But I do have the sound card driver and also my OneDrive which has an impact. It gives me time to feed the fish in the morning.

Once it's booted the desktop is immediate - there's no waiting for things to keep loading. So far it has made everything quite a bit quicker so I am pleased.

I've found windows 10 to be a strange beast, it can take a while to fully settle down and start booting at full speed, especially with fast boot enabled.

  The HP has twice the sata speed as the Gateway so it should be about twice as fast loading, actually didn't realize they were that quick but I had expected a six core with M.2 to load quicker than the HP.   I'd get pretty angry if I put over a thousand into a build, actually I don't know what I'd expect to get. 
  I just googled one drive and as I thought it's Microsoft storage, I've got 4 hard drives and just formatted one 500Gb for additional storage plus the small SSD drive for storage.  It ends up getting formatted as a Master boot drive for some reason and isn't visible in explorer.  I remember running into that before.
Carl2

I don't think I am going to get upset about 14 seconds to be honest...

   I'd say you have a very good machine, something to be proud of, I'm envious really.  It seems my chance to get out of the Quads has come and gone.  Seems it depends how much hardware you have to load drivers for.  Anyways good luck with your Daz work, seems you have them buying groceries.
Carl2

Thanks Carl, yes I am pleased with it. As an unexpected upgrade it's gone well. Now to save up for a new graphics card, but that will be some time. I think the hardware does add to the boot yes, the graphics drivers are pretty big.

Thanks about the Daz work too, I'm still waiting to hear if they are accepted.

Got an email from eBuyer about that first SSD - they found it was faulty, so maybe they could be used in my MB.

I think this is fortuitous though as I get the better piece of kit in the end.