The IPs on archive.ubuntu.com seem to have very different download speeds, is this expected?

[Kit Sunde]

Hello,

I hope this is the right place to report this. As I'm sure you know 
archive.ubuntu.com reports 4 different IPs:

91.189.88.149
91.189.88.152
91.189.91.23
91.189.91.26

The bottom two seem slower especially 91.189.91.26 which currently gets 
speed at around 100kb/s. 91.189.91.26 is faster at 350kb/s+. The top two 
is a lot faster giving me well over 1mb/s and they also behave 
differently by not letting me access them directly on the IP, I have to 
set a hosts header. This is what I tried (repeatedly):

wget 
http://91.189.91.23/ubuntu/ubuntu/pool/universe/n/nginx/nginx-extras-dbg_1.9.15-0ubuntu1_amd64.deb
wget 
http://91.189.91.26/ubuntu/ubuntu/pool/universe/n/nginx/nginx-extras-dbg_1.9.15-0ubuntu1_amd64.deb
wget --header="Host: archive.ubuntu.com" 
http://91.189.88.149/ubuntu/ubuntu/pool/universe/n/nginx/nginx-extras-dbg_1.9.15-0ubuntu1_amd64.deb
wget --header="Host: archive.ubuntu.com" 
http://91.189.88.152/ubuntu/ubuntu/pool/universe/n/nginx/nginx-extras-dbg_1.9.15-0ubuntu1_amd64.deb

It's troublesome because the IP rotates and so at one point I'll get 
decent speeds and at another it will be an order of magnitude slower.

I'm connecting from AWS in Singapore, but are the big variance expected?