Myself and at least a couple others around here see this, not just with the apps store, but other things as well. It also doesn't seem to be consistent (at least that I've seen). In other words, there are times when the app store will not load and no matter how many times I retry, it won't work unless I disable LTE. Then there are times I've had it work very quickly the very first time. There's something odd and I'm just not sure how widespread it is.
Hmmmm.... I am having an issue downloading even on WiFi right now so I'm seeing it as well and it's different from what I was seeing before. Oh, just as I'm typing this I'm seeing very slow movement on the download. Maybe they have some servers offline for maint and are at reduced capacity right now? Who knows.