Hi chard, it is nearly the same. With Financial Spread Betting (FSB) you have to enter a "Stake" per Point and with CFD you enter the Size.
In other words FSB works as follow:
If you want to win 1 € if the FTSE moves up (you want open a Long Position) 1 point, than you have to enter 1 Stake. If you want to win 5 € if the FTSE moves 1 point then you need to define 5 as Stake.
Depends on the provider you have the opportunity to trade the Cash or Future Markets.
FSB usually "rolling" contracts up to their expiry, CFDs have no expiry.
FSB: you can trade with a smaller amount of money than CFD
There are a few other advantages/ disadvantages but like you have already stated both derivatives have nearly the same specs