For me paper towel is great, because if the seed is not germinating I see in 2 or 3 days and can replace it.
Directly in soil is great, but the only drawback is I need to wait around a week to see if the seed has germinated or not, so if I need to start another seed, it is delayed a bit longer.
I have also had some trouble of the shell sticking on the cotyledons when I've planted in soil (I grow outdoor and the surface dries fast) and keeping the seed in paper towel has helped me keep them moist until the shell comes off.
There is no right or wrong way if it works, but there will be a best way for the way you grow.