Most FTP client software that I've seen does not report transfer speed. FTP is generally faster than HTTP transfers, typically by 11% to 50% because it does not have the same overhead. FTP actually gains maximum transfer speed over time. The limiting factor in your case would probably be the physical layer of your LAN. Also, the AZBox is painfully slow due to limitations of processing speed and the small amount of available memory. The designers are asking this box to do a lot! The bottom line... If you have a lot of traffic going on your LAN and your transfer file size is small, expect it to take a while to upload to your computer. The main point here is that FTP inherently gains speed with larger file sizes.
Re FTP software, I was using WSFTP, which shows the rate during transfers, and also after the transfer says something like X bytes transferred in Y seconds. I also just used the old stopwatch method, which agreed.
The thing about FTP working better with larger file sizes, yeah, I guess that's probably true of most transfer methods, ie higher percentage going to data and less going to handshaking. Off topic a bit, but I have a weather web page, where every couple hours, I upload a bunch of gif files showing weather data from the weather station on top of my garage. The files are automatically uploaded by FTP. The funny thing is that before I "upgraded" to satellite internet, the files would transfer in about 1 minute over dialup. When I got satellite internet, the 1 minute transfer became over 8 minutes! I attribute that to extra handshaking, trying to set up the transfer with the inherent delays associated with satellite. I thought that there was a problem with respect to FTP and satellite internet, however when I did some tests comparing the transfer of many small files vs one big file, the satellite internet was 8 times faster with the big files.
I am surprised that you'd say FTP was faster than HTTP though, although perhaps there is more than one way to send data by HTTP. Reason I'm surprised, is that I could stream 40 mbps CBS HD (the old 4.2.0) through my LAN, but FTP seemed to max out at 29 mbps when I tried it yesterday. Although it just occurred to me that the 29 mbps transfer yesterday involved going through the 54 mbps wireless. I guess I should repeat that going between two of my desktop computers.
I also wonder if my specific LAN is overly complicated because several of the computers on the LAN have more than one NIC with different subnets, and the way I understand it, each time a packet is sent out, the computer has to decide which NIC to route the packets to. I keep meaning to eliminate the 2nd NIC, and put everything on the same subnet, but I have about 14 devices and my switch isn't big enough to put all the devices on one switch. I originally put all the video devices (TIVOs, ROKU, PopCornHour) on one subnet, and the regular LAN stuff on the other subnet. Anyway, it could be that my LAN is congested, but I think I demonstrated yesterday that the USB HD was responsible slowing down the transfers a lot.