Weird Browsing Issues

[#1]

Hi all - my first post here so please be gentle lol! I've posted this in the Fibre section as there is no general internet section but this problem has been occurring over the past week even prior to my conversion to Fibre
Basically some web pages load straight away, others are very slow and some simply wont load at all and give me server or page cannot be displayed errors. Checking the sites on 'downforeveryoneorjustme' shopws that it is just me - the sites/pages all work fine
For example I have been trying for 2 days to get to the webpage http://www.currys.co.uk/gbuk/computing/ipad-tablets-and-ereaders/tablets/samsung-galaxy-tab-s-8-4-ta...
I simply cant get there, it sits doing nothing for ages then gives me a timeout error. Yet if I go to Currys.co.uk, click through to the tablets section, find that page and click it then it displays perfectly. However if I refresh, hard refresh or close/re-open my browser it wont load.
I cant log in to my online banking at NatWest. Well not true - given enough goes at it then I can sometimes.
Looking at review sites - sometimes the pages display, other times they dont or they take forever to display.
Last week I was told by PlusNet that there were 'tons' of upstream errors on my line which could affect browsing as the request for the page has to go up before the page is downloaded. They were unable to book an engineer on this due to my impending Fibre install which went ahead yesterday
Since going to fibre nothing has changed. I'm getting great speedtest results (35Mb down, 4.5-6Mb up and varying pings of 20-60 ms), my downloads are great but the browsing issues remain.
The BT WHolesale engineer said that the line faults would not affect the fibre as the faults were on the part which is now bypassed.
The problem is not limited to 1 device, it is the same on both of my Windows 7 computers, my android tablet and phone and my W7 lappy. Firefox on my office computer and lappy, chrome on the downstairs computer and android devices
Facebook takes around 30 seconds to load whilst the plusnet homepage loads almost instantly. In fact virtually every plusnet page loads instantly whereas even the fastest of other pages takes longer. To be honest fibre has made absolutely no difference to browsing speed at all despite making a massive difference to download speed. Youtube is hit and miss, sometimes working perfectly, other times stuttering and buffering like dialup.
Any suggestions? Is this a plusnet routing/caching issue or something specific to my installation?
Thanks for the help in advance

[#2]

Currys website can be very hit or miss, especially with static pages.
Try using the Google DNS servers - 8.8.8.8
Edit your network connection on your PC and instead of "use automatic DNS server" put in 8.8.8.8 and see if it helps.
What operating system are you running on ?

[#3]

Since this applies to Win7 and Android it is unlikely to be operating system caused
It is quite possible that the large number of upstream errors found on ADSL have carried over to fibre as they may be caused by the wiring from the Cab to you even though the BT Engineer said different
Only Plusnet can advise on that unless you have an unlocked modem or are using a VDSL capable router
As a general point a large number of upstream errors could well cause the problems you are seeing
Can you do this speed test and report the results http://www.thinkbroadband.com/speedtest.html?utm_source=mainsite&utm_medium=navigation&utm_campaign=...

[#4]

Worth a double check with the DNS still - someone else had a similar issue on the forum a few days ago.
I missed the Win7 bit (still working and skimming through posts) but dead easy to change on a Win 7 machine to test.

[#5]

Thanks for the suggestions guys.
I dont think changing the DNS is going to be of help as the same thing is happening on android devices as I mentioned - so it isnt really practical to do that and to ask visitors to my house to do it too.
Speed Test results arent of use - I already mentioned the results above and the speeds are good.
I will ask for a line check though and see if that can be the issue. The BT engineer said the fibre broadband line showed no faults on his test but then he was fairly lazy and not as knowledgeable as I'd have expected - I had to explain to him the difference between an RJ11 cable and a CAT5 one and also why his installation couldnt work as he routed the RJ11 cable out of my ADSL Router into the Fibre Modem instead of from the phone line to the Fibre Modem and then CAT5 to the Router
Interesting to note the comment about the Currys website - have to say until this happened I have never had a problem with their site ever (just their prices lol!)

[#6]

The DNS change can usually be done on your router if you prove that this is the issue. Any devices that then connect to your wireless / wired network then get the new DNS details.
Changing it on the one machine will let you check if that is the issue