just some feedback from my side for anyone interested. i decided to try it out and purchased the sx os pro kit via xmods - the timing was terrible because when it arrived the SX website went down for maintenance or something.
you need the website to activate your sx os license, luckily for me they put up a temp website in the interim where users could activate. So i used that and off i went to set up the custom firmware (CFW).
i made a ton of mistakes ie forgetting the sd card when booting to RCM etc but fortunately the system is very forgiving and didn't give me any hassles. i eventually booted into the CFW and the license file (request file) was then written to the sd card automatically - BTW you can also activate from the switch itself provided you connected to the net - i being the sensible one decided to do the offline activation - so i put my sd card back into my laptop and proceeded to the sx os temp website to activate, once done it will write a new license file to you sd card which will automatically activate once in your switch.
Then i booted up again and made my another mistake

i went straight into the CFW and checked my license etc You should actually back up your nand first ! then boot into cfw once that's done. Anyway its all working now. you also need to install the homebrew app and whatever apps go with it. i haven't installed anything just yet as i'm still playing around with the system.
Hope this helps anyone else out there thinking about homebrew. i don't intend to go online again with my switch so this works for me, for those of you who do still want to go online you can apparently set up something called emunand that makes it safe/r to do so.