Speed test's why the massive difference in upload speed results?

[#1]

If i do several speed tests selecting different servers on speedtest.net  the upload side of the tests vary by a considerable amount  most are sub 10mbps  only a few are able to give a result that is near what upstream throughput should be, 19-19-5 mbps  
Even the BT wholesale speed tester rarely will give a result for the upstream that is somewhere near  the highest I've seen is 15mbps
And most other sites including the tbb speed tester are sub 10mbps  for the upstream , Why is it that no one seems to think that upload speed performance isn't important ?
http://www.thinkbroadband.com/speedtest/results.html?id=137969359122791389316
http://www.speedtest.net/my-result/2980125011
And  some tests that are nearer to what the upload speed actually is
http://www.speedtest.net/my-result/2980130245
http://www.speedtest.net/my-result/2980133799

[#2]

as you will notice with all speed testers there unreliable unless your referring to the test login one BTW provide via the local exchange (it has a single user limit though so you might wait a few hours for it to be free) all of the other network testers (including BTW) are subject to capacity issues (how many users they can actually respond to simultaneously) and as happened with speedtest.net 2 years ago, the numbers can be way below actual throughput of your service (at one point they were showing higher speeds on there usa east coast servers than on there uk ones for uk customers)  they all carry a disclaimer that there data is only an indication, and since those things are nearly all sponsored by one isp or another the results are always skewed to show favour.
the btw speedtester isn't any different (unless you use the test connection one) and it would be really good if PlusNet had some form of widget or app to show % of expected speed available (even with a 10% margin of error it would likely be better than most speedtesters)

up or down its all the same, unless your on btw and getting a red line (where its normally green) you shouldn't have anything to worry about.
and just hope wherever your uploading to doesn't use sky as there isp.......they throttle uploads and leave downloads alone ....

[#3]

Whilst i am aware that speed test sites only offer an indication of the real throughput but since i got fttc back in april  apart from think-broadband  these results have been fairly static over the months, think broadband used to until this week give upstream results close to the mark ,why the sudden change?
I would be interested in what upload speed results other plusnet FTTC 80/20 unlimited customers are getting  from the bt wholesale speed test and think broadband speed test for comparison purposes
As for my comments regarding that upload speed isn't seen as important than download speed is, this is industry wide, BT openreach don't even give it as much thought ,ie they don't launch products with symmetrical  speeds even with FTTP  is only 30mbps , why not 50 or higher ? Hyperoptic  are able to do this using the same tech ,

[#4]

I did a few tests recently,
and achieved 46.83/15.71 ip profiles were 60.95/20 respectively
and then I did another that gave
68.37/15.83 with ip profiles of 70.97/15.83
and just now I did one which gave
58.26/15.39 ip profiles of 60.95/20
doing the ookla speed test I get 56.71/17.10
and both of them give a different result every 5 minutes
whats even better is the bt w tester shows a different ip profile for the line every time I use it despite the modem having been switched on for ages and only the router having been turned off, which leads me to wonder if the modem isn't doing something the router isn't recording ...

[#5]

The results from speedtest.net are more or less consistent for me,using the same severs,as was the think broadband speedtester, the only real variation being during peak time some times, as for the BT wholesale speedtest, that doesn't give much consistency on both up and down, it has periods lasting weeks where the upstream wont climb past 10-12mbps yet today it's showing 16-17mbps ,but the IP profile has remained the same since install day