I've lived in highland park my whole life. It's definitely LGBT friendly. Most of the pros have to do with its location (relative to the train, highways, and Rutgers and Edison), so I'm assuming you already know all those. Other pros are that it's very walkable, it has nice parks and a big library for the town's size, and it's quite a diverse town – in my graduating high school class of like 90 students, we had native speakers of something like 20 languages (although a related con is that despite the diversity, the housing is fairly segregated with most nonwhite people living in two areas of the town that are mostly apartments while the rest is mostly houses). Cons are the rent/tax, the light pollution, the housing segregation, and that's basically all I can think of.