I think cliffhangers are fun, depending on how it's done. (I didn't intend for that to rhyme, lol.)
My first round of beta readers mobbed me at work or flooded my email box because I dropped a bomb at the end of my story that no one saw coming--and just left it at that. Well, along with a couple other surprises. I believe in things--whether good or bad--happening in threes. So the end definitely had a few things going on which left folks wanting to know what happens next--and thus why I began writing book two right away.
BUT, then I remembered that I, personally, can't stand non-closure. So I added an epilogue which tied up some loose ends, enough to satisfy folks, while the cliffhanger still left readers looking forward to the next installment. I just pictured myself watching a movie that had me on edge, then ends abruptly without any closure--which drives me nuts! That, alone, often ruins the whole movie for me. So with that in mind, I think cliffhangers are nifty as long as you give your readers somewhat of a satisfying ending along "with" it.
I read a 265 page book recently, which had an ending that was frustrating because she ended it in the
middle of action! Grrrr. It was crummy because nothing much happened in the first hundred pages, yet I continued to read just out of curiosity sake, then just as it got interesting
then she ends it. Good grief. I'm so annoyed by it that I don't intend on buying book two when it comes out. I certainly don't want readers to feel that way about mine, lol.