Hi - I'm not sure where the situation actually lies, but I'll start here...
For work, I transfer a lot of data to the office and back home again (over FTP usually). I've noticed that when I transfer a file from home to work it'll often give a speed of about 100K. However, every third, fourth or fifth time this speed will be 2.5M (what I'd expect). If I restart an upload a couple of times, I'll eventually get a good transfer speed.
My office connection (about 15 miles away) is a solid 100/100 (in the process of upgrading to 1000/1000). Transferring to and from other locations at work is consistent.
When I run a speedtest at home, I always get a decent 20 upload.
Any ideas? I'm guessing it's something to do with the route that is taken, and with uploads being more important I don't really want my speedtest connection to check out fine only to find out that my real world upload is random.