Frame talk

I have always read and overheard talk but never really took it all in, but
now when I'm shopping around its worth knowing.

Assistance appreciated ...

Benefits of triple-butted heat treated TIG-welded compared to double butted.
Benefits of a frame with a replace end?
Then, what are the benefits of a frame with replace-end & carbon swingarm
compared to a frame with a replace-end?

Are there any links where I can read about this?

Although I would very much like to hear your thoughts on the above.

Thanks in advance.