On the upside, Dive Palancar is professional, safety conscious & orderly with nice, well-equipped boats. It's situated well south & close to many of the best dives, so rides are short & you return to the resort for surface intervals. Can snorkel & do tune up dives right off shore, although there really is not much to see.
On the downside, it's a high volume op with capacity to take many divers, so don't be looking for small, fast 6-pack boat trips. Also, it serves a mixed crowd, including lots of newbies, so expect "lowest common denominator" diving with little leeway for more advanced divers to observe their own profiles. If you are an experienced diver who wants more profile freedom & to see some of the more challenging sites (they don't go north to Barracua, San Juan, etc,), I'd definitely suggest another op, like Aldora or Dive with Martin. Nearly all ops will pick you up at the Allegro dock.
Have fun.
DocVikingo