Do condoms have an effect on sensation?

Yes.  Especially for men, as it puts a barrier between their most sensitive erogenous zone and the vaginal wall during penetration, diminishing the pleasure he may feel from moving against them.  Both partners may dislike lubricated condoms, especially if it isn’t needed, as too much lubrication can lessen feeling.  In general however, lovemaking with condoms relaxes couples and makes them feel more confident, which has a knock-on positive effect on sexual pleasure.