I am a member of Golds Gym Vashi. It is near Vashi railway station and in Raguleela mall.
Though the gym has good equipment and ambiance it has been plagiarized by non maintenance of its premises. Moreover the condition of Raghuleela mall has deteriorated over the years.
On the contrary the Gym has good spinning, zumba, cardiovascular and weight training zones as well as a swimming pool on the 4th floor of the gym, though it is only 5 ft deep.
Trainers here are also very good and are pretty helpful.
Parking is available in the Raghuleela mall premises which is free for the Golds gym members.
All-together I would recommend Golds Gym in Navi Mumbai premises.