Eh, there’s something to be said for experimental periods in my view. Sometimes you try out new programs that you wouldn’t think would be useful but end up becoming essential. And then culling mercilessly anything that turns out to be not useful, or overly complex to maintain, reducing your maintenance burden.
Try KOReader. It’s mainly for e-ink devices (initially, Kobo devices) but it handles PDFs better than most applications and gives you various options to address them.
It’s still not going to do miracles on smaller screens like phones, but I use a Kobo tablet/ereader and it works very well there.