Looking back now at my little "arsenal" I also believe in "Cartridge Spacing" but I really didn't know I was doing it!
It makes sense.

I tend to also buy guns that are chambered in "different" cartridge as some of you mentioned you do. I'm not sure why though!

For example:
I simply LOVE my 444's. You don't know how many times I've been asked"why didn't you go with the 45-70?"
My only answer is, I personally prefer Winchester lever guns, and at the time 444 was the biggest they offered so that's what I bought and fell in love with it. I've since bought a 15" Encore barrel in 444 and I'll be darned if someone didn't ask me the same question! "why didn't you go with the 45-70?"

I'm now looking into buying a .264 Win mag barrel for my Encore, and I've been asked "why don't you geta 270 instead?"

Heck I don't know? My father-in-law has a 35 year old model 70 264 win mag and I love it! I've watched him shoot a 5X5 Bull in Colorado and lots of ground hogs and yotes with it, plus he said he's shot a couple of mulies with it.
I guess I just think it's agreat, and very effectivecaliber. No other reason for wanting one.

I just really wanted to see if anyone else picks out guns or cartridges based on weird reasons like this!

Keep em coming guys, I think this kinda thing is neat!