I', suprised that it took this long for your son, but am glad to se it happen.
I married my present wife who's son was 11 at the time, who made the decision when her son was 10 to have him stay with his father (married and she had kids already, which was better than single working mom...). The tough part for her was her ex was in Austin, TX and she was here in Atlanta, GA.
When I first started dating her, she said she was going to drive out to see him one Friday and come back on Sunday. I immediately quashed that idea and said I'd fly him here for 2 weeks or a month (depending upon what activities he had going on during the summer), and have done that ever since.
We just flew to San Diego for his wedding (yes, we've been married 18 years now), and I haven't regretted the time or money spent in helping to raise him in any way shape or form.
At this age, boys need fathers more than mothers IMO, and I don't believe I am a male chauvinist pig in stating this.
I hope everything works out well for you and your son (I've met you both at what used to be SEZ), and look forward to seeing both of you again!