Praise be to Allaah.
Yes, there are benefits of circumcision insofar as it is part of the sunan (ways) of the Prophets and is part of the sunan al-fitrah (acts that befit the natural state of man). It is cleaner and healthier in terms of urination and intercourse, and prevents infection, etc. These and other benefits far outweigh the pain caused, which is less for infants than for adults.
Moreover, a number of the scholars have said that circumcision is obligatory for males. Ibn Qudaamah (may Allaah have mercy on him) said in his book al-Mughni: Circumcision is an obligation for men and an honour, not an obligation, for women. This is the opinion of a number of scholars. Ahmad said: It is more of an obligation for men, because if a man is not circumcised, this piece of skin will be dangling down over the head of the penis and it will be too difficult to clean left-over urine properly. It is not so strict in the case of women. Abu Abd-Allaah said: Ibn Abbaas used to be very strict in this matter, and it is reported that he said that no Hajj or salaah would be accepted, i.e., from the one who is not circumcised. Al-Hasan was more lenient; he said: If a person enters Islam, it is not essential for him to be circumcised. And he said: Black and white people embraced Islam, but not one of them was checked or forced to get circumcised.
The evidence that it is obligatory is the fact that covering the awrah (private parts) is obligatory, so if circumcision were not obligatory, it would not be permissible for the one who wants to be circumcised to uncover his awrah for this purpose. Circumcision is one of the signs of a Muslim, and like the other signs, it is obligatory. If an adult male embraces Islam and is afraid that circumcision would be harmful for him, then he is excused, because a person may be excused from ghusl, wudoo, etc., if he fears that they may be harmful for him, so it is more so in the case of circumcision. If a person is confident that it will not be harmful, then he has to do it. Hanbal said: I asked Abu Abd-Allaah about the Dhimmi (non-Muslim under Islamic rule) who embraces Islam: did he think that he should be circumcised? He said: There is no alternative to that (i.e. he has to). I asked: what if he or she is advanced in age? He said: It is better for him to be circumcised, because of the hadeeth: Ibraaheem was circumcised when he was eighty years old, and Allaah says (interpretation of the meaning): it is the religion of your father Ibraaheem [al-Hajj 22:78]
So our advice to you is to go ahead and have your son circumcised by someone who is skilled and experienced. The Prophet (peace and blessings of Allaah be upon him) said: Five things are part of the fitrah: circumcision, removing the pubic hair, trimming the moustache, cutting the nails, and plucking the armpit hair. (Reported by al-Bukhaari, 5441)
May Allaah help us and you to do good.