Well a guy would have to have both a big penis and small penis both at the same time to know....so its a weird question
Surely if you've always had that size penis it's all you'd know and be used to probably wouldn't be difficult...anatomically speaking there no difference aside from the size anyway.
I wouldn't think so, I'm average size and have jerked off guys with smaller bigger cocks. They all work the same in my experience, On a quick side bar one guy wanted me to keep stroking him after he came, even though the over stimulation was killing him I kept going until he came again. This led to ruined orgasms for me where I would be brought to the edge of Cummings four times or more before being allowed to cum.
I couldn't answer the question, so I asked my wife who gave hand jobs to a number of guys in college. In her opinion, it made no difference whether a penis was large or small, masturbation was the same.
The bigger ones felt better, but the best was an average size cock on a guy who knew how to please her.
I was talking to a very experienced friend of mine about small cocks. She told me about jacking off a guy with a 3" dick. She says she had to change her technique to one or two fingers (I don't remember which) as he was so small. If she used her normal technique, there wasn't enough room to stroke. She said he made up for his tiny size in the amount of cum he shot. it was a lot. She also told me about sex with another guy with a 3" cock. She couldn't feel a thing and didn't even know when he was in there. He was engaged, and she felt sorry for his fiancé.
I have a friend who has a small 3 inch cock, he's been married to the same girl for over 40 years and has 4 grown up children, and they are devoted to each other, so he must be doing something right, but the original post is about masturbating with a small cock not having sex, I have a small cock but masturbating to me is a wonderful sensual feeling, I masturbate at least twice a day sometimes more achieving amazing intense ejaculations. In the end you've got what your born with,