Voting to Leave.
The EU is a sinking ship. Look at the referendum held in the Netherlands recently re: Ukraine and how BLASÉ the EU are about overriding democratic process. They do not give even a single F.
Turkey will shortly join gaining full access to the Schengen zone. Who knows which member states could join in future.
Wage disparity (i.e. wages in the UK being higher than the rest of Europe and our more robust, more valuable currency) we'll be destination #1 for any citizens of future members joining, as per. We have just raised our minimum wage.
If we do vote to Stay, we'll give the undemocratic EU carté blanche to override our sovereignty and continue to give us the short end of the stick. They'll never let us vote on it again.
Limiting benefits to new arrivals hardly matters when you can buy a house for 10% of what it costs in the UK, in Eastern Europe. Our benefits bill is mostly pensioners on housing benefit to pay rent.