How have you managed to find someone with the same birthday and almost exactly the same ascendant? Unfortunately I don't have much time in my hands, so I'll just have a look at the house placements (which are extremely significant though).
What you should do, is to have a look at your individual birth charts, see what kind of relationships you two are looking for and tend to have, and estimate how good a match you are in that regard. Difficult aspects and placements (let's say, for example Mars or Uranus in the 7th) are indicators of more considerable than average troubles with relationships. So even if the synastry looked like a match made in heaven, there'd bound to be troubles ahead.
Venus and Mercury in the 11th are nice placements, not the absolutely best for a romantic relationship, but still pleasant. Mars in the 8th (both ways, if I saw correctly) is a major indicator of powerful sexual attraction, if other factors give any kind of support to this view. Moon in the the 4th is case sensitive. In the worst case scenario it can bring out competitiveness, but most often it probably creates a kind of familial bond. In any case the effect could be described as "siblingly".
Your Moon is in his first house, so it's possible that you identify with his emotions and his reactions to different circumstances quite well, and you feel that you two can enjoy the same things. It's a nice placement.
Unfortunately, I don't have time to look at the aspects or the composite, someone else could also write a word or two about your Suns being in each other's MCs (not an ideal placement for a romantic relationship).
How long have you two been together? Are you still at an early stage or have you been together for years and years and still feel "inseparable" as you said? When it comes to synastry aspects, for example, it takes a while for many of them to kick in, so it's not advisable to compare a relatively fresh relationship to its chart and jump to a conclusion that they correlate poorly (I say this as a general notion).
I hope this helped a little.