Definitely for experienced travelers only! First time in 7 years of travel someone tried to steal my phone. These people are friendly, mostly. But there's a not-tiny portion of locals that are a combination of unfriendly and hostile. You can sense they don't like you and I'm unsure of the reason. A sheisty culture. Besides that, it's a shitty city. Not walkable but also not a great selection of large malls to hang out in. Dirty, hot. A very nice selection of Airbnbs, but it's an expensive town.
I've also been to Juan Dolio which was disappointing. It's said to be better than Boca Chica, and having went to BC first, I would assume this to be nearly impossible. In JD, absolutely the bare minimum was done with the beach including plastic chairs. At least in BC there are some nice spots and it's closer to Santo Domingo.
Santiago de los Caballeros is about 40% the size. It's greener, not cheaper, Airbnbs are shittier, the people may be slightly nicer, and the girls don't seem to be cuter than Santo Domingo. It is slightly more walkable in that the sidewalks are actually paved and absent dog shit. Plus it's more enjoyable to walk due to the better climate (not as hot and fewer clouds).