Should I pursue a relationship with with my birth father?

I am 34 and I have always known I was adopted and have nothing but praise for my adopted parents. Ten years ago I found my birth mother, and two unexpected biological brothers. This has been largely positive, though I have a few 'betrayal' issues I guess. My birth father I only met a couple of years ago. He had ten years to make contact, but it never happened. Finally, in not the most ideal of circumstances, we met. We talked, but I didn't feel any bond, and further meetings haven't been strongly pursued by either of us. I am now wondering whether I should instigate another meeting, or let it lie. The pros and cons I see are these. PROS> We could develop a mutually beneficial relationship and I could compare myself to him and identify possible personality traits that could answer questions I have about my own personality. CONS> As suggested by our first meeting, we could have little in common and i couold end up feeling more rejected than before. There is also the guilt factor that I already have a fine father in my adopted family, and perhaps I don't have a 'father-shaped hole' in my life that needs filling. I worry that the end result is going to be two adults with little in common struggling in vain to connect. My birth brothers have not had a particularly positive relationship with their/our father, and I understand that his current spouse is pressurising him to keep us apart, and he is compliant with this. Close friends feel that I should pursue a relationship, but I feel that they have little understanding of the complex feelings of the adopted child. I have been worried lately that if he were to die and i had not explored our relationship, I would regret it. Now however, I am feeling that he is little more than a sperm-donor, and my real allegiance is to the people that brought me up in a loving, supportive environment. I would appreciate any experiences from other adopteees in a similar situation.