There have a been a lot of posts lately from builders who are very enthusiastic about using boutique components in anything they own. This is great, after all this is DIY. But there is something very important to keep in mind about this. These builders did not have a stock Kaiju to listen to in order to make some decisions about where they would like to sound to go with the parts they changed. Thus there is no particular justification for the changes other than the desire to personalize the kit. Will there be differences? Probably. Will they be differences that you like? I have absolutely no idea, and neither does the person who has implemented the mods.
I have also seen a post of someone lamenting not buying Paramounts rather than the Kaiju. As great as the Paramounts are (I have been using them in my system for 8 years), they are a step down from the sonic attributes of the Kaiju from a technical standpoint. The Kaiju has better transformers and plate chokes - better bandwidth that is audible. I will be replacing all of my Paramounts with stock Kaijus over the next few months and I know I will be reaping the sonic benefits of doing so because I have compared them side by side.
I point these things out because some may mistakenly assume that the Kaiju needs boutique part fluffing to be good. There area lot of technical considerations - things the boutique part manufacturer will not often tell you - when choosing a component. Things like voltage, current and temperature ratings, rated lifetime, size, materials science, reliability and even ease of installation come to bear on the decision. These are factors that we have been considering for 20 years now. And we design our kits for a ten year sales life span. So we don't take those decisions lightly.
Kaiju is intended to be our best sounding, top of the line amp. When I set out to create the new Limited Edition kits we had some discussions about what to do to them to make them special. The upshot was that we felt the cosmetics would be interesting to work with since the kits are unfinished. When it came to the circuit components we just didn't feel the need to change anything, since the deliberation over the best part for the job had already taken place in the initial design.
So, by all means, mod these kits to your heart's content. But be honest with yourself and do it because you want to personalize them. Because there is no way to tell if some part change is for the better unless you have listened to the amp without the part change first, and changed only one part at a time before listening again. And even then, you can't assume that someone else will like the change. Modding is best done in a methodical fashion. Change one thing at a time and listen. Don't take other people's word for what will work for you. And never forget that this is really all about enjoying the music.