I don't think the 'deal' really changes anything other than really get the debate started. After all, the items under discussion are really quite insignificant relative to our overall integration with the EU.
What the deal may represent is our ability to shape and direct Europe from within. We've now got decades of experience under our belt being 'in'. We do not have any recent (past two generations) of proving that we can effectively operate being 'out'. It is highly challenging to put forward a case to say that we, as a nation, are capable of operating better in or out.
So you could say the better the devil you know, and stay in. It is a known situation, and our recent history shows us how we are able to cope with it. The unknown is electing to leave - those experiences are so long ago and in a completely different era that they're simply not relevant.
My emotional response is that from a cultural perspective, Britain does not cope well being in. Even if we do put membership to our advantage and influence direction, the nation as a whole does not appreciate it. We tend to think that we're bigger and better on our own. So I think it is time for a dose of our own medicine and test that cultural and emotional belief, and opt out. Then, if nothing else, we'll learn whether or not we are capable of being a better and more productive nation with greater control over our own direction.
And if we're not or if we are, then we'll know the answer and the way ahead. At least if we're out we can stop blaming somebody else for our woes. Apart from the Chinese and all their cheap steel, of course...