As someone with a few thousand hours rotary and a few thousand on medium sized jets (737 & A320) I would say neither is better or more difficult. They are just very differant.
I found landing on a rig on a miserable night on the North Sea with the helideck in the turbulent sector no more or less challenging than Landing a 737 in 35kts of crosswind on a wet field length limited runway at night.
Performance & the ability to carry a little extra fuel is generally (but not always) less of an issue in a jet but energy management usually has to start earlier.
For sure it is harder to learn to fly an R22 than a Cessna 152 but when it comes to operating a public transport service differance in difficulty level is minimal but the logistics are poles apart.