Switch from Voda to Sky...speed query

Hi all, just trying to confirm something.
If I switch from VF (rural exchange...currently speed-testing at anything between 5 and 9 Mbps) to Sky should my D/L speeds remain the same.
I'm assuming that either provider is piggybacking on the Eircom network and neither provider has a direct connection to my D/L speed.

Main reason for changing is the unlimited D/L cap with Sky. I'm on a legacy plan with VF (300GB per month) and to upgrade to capless would mean losing some add-on's I currently have. Changing to Sky would keep my bill within €1 of what it is now and I would gain free calls to USA (handy for Family).

So, basically, is there any reason why my D/L speeds should change if I move provider ?
Thanks.