My girlfriend have just bought a gel saddle for her hybrid bike. She does day trips with it (30-50 kms) and a bit of commuting. Some say this saddle is useless and she should buy bike trousers instead. What do you think?
Generally you will find, for getting started a gel seat may help. As do padded shorts.
However, once you ride regularly, and build some muscle and tolerance around your sit bones, you will find it annoying.
So it is a good gateway drug to getting used to a saddle. Generally people find that narrower and simpler seats are more comfortable, once you start riding regularly and build up your seat area.
I think most of the current gel seats are worthless -- like too many bikes these days, built to sell, not to ride on. There used to be the old TushCush/HydroSeat sold by Nat Calvert that was pretty good (it was a bladder and leather cover for a standard seat), but he sold the business to someone else who ran it into the ground.