I don't like them when they aren't adjacent to the main lane. You end up outside the zone where drivers are looking for fast vehicles.

An improved shoulder wide enough to not have storm drains or debris to deal with is ideal. You can enter the roadway proper as needed to take the lane or prepare for turns like every other vehicle. You don't get abuse from ignorant drivers who expect you to stay in your designated space.

As a recreational cyclist, I wouldn't like dedicated cycle lanes that had a too-low (and enforced) speed limit, for example.

I do, I have been driving my bicycle to work for 12 years now. Not only I prefer regular roads, which are much better, whenever there is a segregated lane I avoid it. It is very obvious what segregation is for when you get hostile behavior on the part of motorists when you ignore the cycle lane and they complain that you don't use it.