Advantage of having more than one keyboard? Maybe one for different languages

[roaming pear]

Soooo....
I have seen tons of people have more than one mechanical keyboard...  I Was wondering if there is any advantage to this?

I'm thinking of getting a Japanese layout keyboard for when I type in Japanese, but

1) I'm not sure if I should spend 100 or 200 plus dollars on a keyboard only to write Japanese when my other kayboard can already do that, albeit it doesn't have the Japanese layout and converts romaji input to hiragana / kanji...
2) I just got my first one, and I don't want to regret my first purchase if my second one is a better quality... To those who have multiple keyboards: what makes you use one keyboard over another? Is it depending on your mood? What would make you use an inferior keyboard when you have a better one in terms of key swithces, and build quality?
3) I'm jut not sure if it is practical.  Are there any advantages to this?  Or is it mainly a collector thing? (I am insticntively a collector, but I'm trying to resist the temptation and only buy things that I Will use)
4) If I have one keyboard with an English layout and one with a Japanese layout, Can I just switch between the two very simply? or do I have to adjust the keyboard software inside my computer?  Like would I have to say, take "hiragana" input as opposed to what very it is set to before? Or does that automatically change once I start typing on the other keyboard.  I am assuming that I have to change the keyboard from EN to JA at least. 

[davkol]

A way to avoid Repetitive Strain Injury is to avoid repetition. I rotate several pointing devices because of that. Dunno, if it works for keyboards too, but it feels nice to rotate more kinds of switches, my fingers enjoy them more then (I use scissor switches, linear MX and stock MX Clear most of the time). I keep more keyboards with different layouts as well, because the ErgoDox is great and stuff, but I sometimes prefer a non-split layout (for traveling or occasional gaming). Moreover, I have more rigs, which implies need for more keyboards.

...and yes, I rotate several kinds of physical layouts without even thinking about it. ANSI, ISO, columnar, grid, you name it.

[Razor Lotus]

On geekhack the answer is always yes, you need another keyboard, whether you need it or not.

I myself have 1 keyboard. I'll probably be getting another to put another keycap set on it and also to use at work and another for home.

[Defect]

For me it's about building and modding and finding different boards/layouts that I can rotate weekly.  I am blessed with a healthy paycheck so I took this up as my hobby and am appreciating every aspect of it.

All my work is on a keyboard and my hobby is keyboards.

[Firebolt1914]

I just have keyboards for every location where I need to type. I'm also using one of them as a keyboard that I don't mind if it gets abused (but not too bad).

[pichu23]

I've got 2. Well 3. Third one hasn't been assembled. 2 60%'s & 1 TKL. The layouts are the same & I don't see a point for me to try other layout. ANSI for me is the best layout for me. I've been using ISO keyboards in my university here in the UK & I really can't stand the big ass enter key (Sorry), the position for "@", and that left shift key is just too short. For now 3 is good enough for me but I might get a GH60 in the future. 60%'s are so nice to use and they're so portable. !

[katushkin]

I have a board for every computer. Plus two extra. And they all have different switches.

So I don't know. I like swapping them over and just having a different experience now and again.