I'll be quite honest. I think you should not go back to the ex but also I do not think you should stay with your current bf. I think quite honestly neither choice is a good one for you right now.

For the ex, you've laid out a few things that are common between you and some reasons for a relationship but many other reasons why you know it hasn't worked and if those thngs have not changed no, you should not go through it with him again, what afer I don't know how many times you have already tried.

With the current boyfriend, you have some good points to be with the person but the fact is the most important thing is not there. You are NOT in any way committed to him, he's a convenience boyfriend because you do not want to be alone. I don't say this lightly either I know it's not an easy thing to hear but the truth is, if EVER you say you are with anyone it should be with the exclusion of others (unless you choose an open relationship and from what I've heard I don't think that's the case) and with your considering your ex still, you haven't taken the new boyfriend with the exclusion of others. That is a MUST or you must let him go. It's not fair to him.

Take some time alone. BE your own person without the dependence on being in a relationship and find yourself. Trust me, it's something I recommend almost everyone do if they haven't already. I've done it, not by choice, but I have and found I've grown more during my singlehood than I ever have in any of the relatioships I've been in.

Hope this helps.