As one that has been cut when I was only a couple of weeks old which was, religion aside, a norm back then in many parts of the world I have done extensive research into this.
Firstly there is absolutely no evidence from any formal case study that proves one way or another that a sex life, or penile sensation is impacted in any way. One thought is that skin has many nerve endings and thus by removing skin you are reducing the total potential sensation (i.e. reducing the total square inches of skin). This is a fallacy as with that mindset you would then assume those that have a micropenis would take a very long time to ejaculate and that a person with a huge penis, is more likely to suffer from premature ejaculation. Neither are true. It seems that brain function adopts as you grow to these variations.
One thing that is recognised with circumcision is the skin condition of the actual gland (the head). Being exposed and allowed to rub against clothing etc can impact the condition of the gland skin. Penile care is often neglected by males apart from the usual pulling back the foreskin for a quick wash. Many medical professionals recommend further care especially with a circumcised penis to ensure the penile skin itself (the corpus) is maintained to a healthy level. Personally I use a skin treatment called Man1 Man Oil (unfortunately isn't cheap) which is a daily treatment of cream to moisturise the gland and the corpus. It has been reported, as in my case as well, that this daily cream also increases sensitivity after a month or two. Being one that has sex almost each day of the week I have noticed that using this cream has not only kept the gland (the circumcised penile head) moisturised but also resulted in a far healthier looking penis that is also reported to be nicer to touch. The enhanced sensitivity has been a great bonus.
Another course of action I undertook was Traditional Chinese Medicine. Penile use, it's sensation, its erection capability etc under Chinese medicine all comes from the Liver. I found that after several weeks of Chinese herbs and Acupuncture I suddenly found myself waking up in the middle of the night with a rock hard erection again. Wow, was that a real eye opener, age has not gotten to me, I was back to my youth again. One very important side effect to consider with this type of treatment though. As one gets older they can often begin to experience a chemical imbalance in their brain to do with Serotonin. The chemical Serotonin is what helps to keep our brain balanced in the area of emotions and when you lack Serotonin in the brain (not liver) you can suffer depression. The generally accepted treatment for this is selective serotonin reuptake inhibitors (SSRI) such as the tablet Lexapro. Now this is where things get interesting as a side effect of a SSRI such as Lexapro is a decreased interest in sex plus an SSRI takes a couple of weeks to really begin working as it is absorbed into your internal organs, especially your Liver.
So, we have a penile problem caused by your Liver, a drug you need to stop depression that decreases your sex drive and resides in your Liver. Chinese medicine cleans your Liver out so you are back to mid night power erections and then suddenly you fall in a heap from depression even though you are taking your Lexapro tablet. What do you do???
Firstly be fully aware of the potential side effects and very clearly advise the Chinese Medicine practitioner that you are on a SSRI.
In summary...
There is no clinical evidence that circumcision adversely impacts your sexual activities
Every male should take penile health seriously including moisturising and cleanliness
Be aware of side effects caused by interacting treatments when considering different sexual and penile enhancements
My 2c worth and I hope it may help someone