I would recommend present-day Hersheypark over any given year of Great Adventure, let alone this year. The only thing (IMHO) that SFGAdv has going for it is El Toro, which is running rougher than it has in the past, and some would argue Nitro (but I've never been too impressed by it).
Hershey has an absolutely insane Intamin hyper, a surprisingly-good RMC hybrid, a unique Intamin looper, a classic Schwarzkopf, a better B&M invert, a drop tower (3 of them, actually), a screaming swing, one of the only log flumes with a jump at the end, a splash boat ride, drive-em cars, a much better atmosphere, better food, free admission for 2 hours the night before your visit, an included water park (that is admittedly too small), etc. etc.
As for the Safari, if you want to ride the truck through instead of driving your own car, then yeah you need to go to the "Wild Safari Base Camp" outside of the park next to the drive-through entrance. It's considered a separate park.