ipxe speed with http

[warthur]

I am currently booting some CentOS 7 servers with with gpxe (From my understanding outdated for 7 years now). I'm getting a 500mb .img file using a gpxelinux.0 file, but it takes about 10-15 minutes to download the file. It doesn't really make sense as once the server is up, I can transfer the same img file to it in about 2-3 seconds.

I think I'm interested in using iPXE chainloading following the instructions here: https://coderwall.com/p/0sq9gg/how-to-build-ipxelinux-0

A few quick questions.
- Does using ipxe rather than gpxe offer a much greater transfer speed for images over http?
- Does anyone have any recommendations on how best to do this with Centos 7, and ipxe?
- Does chainloading with the "pxelinux.0 embedded" like the link above offer a faster way to boot large image files over http? If so can we continue to just have a HEX file to match the IP subnet with the boot options in it?

Just having a hard time finding good documentation on this. It seems like a lot of the how-tos online are just doing outdated pxe boots.