Read the Keven Myers' column, and agreed, he makes some valid points.
His last point is particularly telling - criminalisation will not halt prostitution, but will drive it further underground.
This will make it less easy to monitor, and of course the money will attract violent pimps, so it could well make the situation worse.
Basing the laws on the Swedish model is interesting, because Swedish society and laws are so different from ours that thinking this could work "because it works in Sweden" is not a valid stance to take.
The Gods are just, and of our pleasant vices
Make instruments to plague us