I've spoken to a few training centres and my college on this, personally i'm not doing the 2391 and waiting to do the 2395 early next year. As my tutor said even though 2391 is a very reputable qualification it may end up that on your CV having 2395 would be better to future employers, In job descriptions they may well be asking for 2395 and not 2391 qualified. Not sure how much difference it will make but he kind of makes sense. Same as when they transitioned from 16th to 17th edition. I have also been told not to bother with the 2394 as this is exactly the same course as the 2395 however it doesn't cover periodic inspections, and if you ever have to do these you would need to go back and do the 2395 which means paying twice.