Moving from 76Mb to 6Mb - what pain will I suffer...?

[#1]

Moving house.
My old address I have the 76Mb service, of which I get 72Mb down and 16Mb up.
Been told that although my new exchange is fibre enabled, I can't get it to my specific address...and will end up 6Mb down (not sure what upload). There is no date either for it to be installed. Simply 'assessing options' on the BT site.
I want to stay with Plusnet either way.
In what ways am I likely to suffer apart from the obvious (download times etc).
We are all heavy users in the house in terms of browsing on phones, tablet, laptop, download from Sky on TV and of course the game consoles.
Am I likely to suffer drop outs, slow downs when using multiple devices? Does the supplied Plusnet router offer a quality of service option for me? (assuming I will have to send back my fibre router and get the standard ADSL variant). It's perfect now, we can use everything at once and don't suffer at all, it's going to be a big, big change.
If anyone can offer any thoughts, it would be much appreciated.
Thanks!

[#2]

Hi,
Yes its a shame that BTW cannot offer fibre everywhere.
I think in short if using one service you'll not notice much difference.  I get a synch of around 5Mbps and can watch iPlayer on standard resolution on one device.  If someone also tries to run a chat service (e.g. Skype) at the same time, they both buffer.
QoS is not going to help you, as that simply manages the US priorities, which is not the side of the link which will be saturated.

[#3]

Hi Suarez,
As Townman infers you might have problems trying to stream to multiple devices. If you did watching in SD rather than HD might be needed.
Otherwise you should fine 6mb still allows you to make two uses of the connection at once and shouldn't present too may barriers or problems.