Really?
Ah, well you can get administrator access to your Android phone, just like you can on your PC. We call that rooting. It is NOT the same as jailbreaking an iPhone, but many people compare the idea that way.
And just like on your PC, you get the option to install more and make a good thing better if you can run with admin privileges.
There are good enough camera apps that come with the phones, and some good choices in the Play Store to try.
But - with root (admin privilege) you can install much more comprehensive apps and get them to work at the best level with your phone.
And as it turns out, there are professional photography application developers that work on the pricy DSLRs who have found that they can contribute a lot to us - with root access.
The guy I know making the raw image camera, for example, has my M8 camera modified as I described and another app modified to work on several Samsungs, maybe one of your favorites.
I have a second root camera app by another guy, who started out perfecting the jpg compression problem on the LG, succeeded, applied the same mod to the M8 camera - and that gives me not only better detail but far better color. And I know there's always someone like him doing the same for Samsung.
Personally, I recommend it, but I admit it's not for everyone.
My problem with the review sites is that they give the impression that they have THE answer.
The truth is that the camera app is one of the first things improved by a manufacturer update and sometimes those comparisons are stale a month later.
And that's true in all the categories.
Which I think is why the OP said, I read the reviews, what do you owners think?
I think that they're both great phones and the OP is right to ask owners - because the reviews don't prove anything. They're stale.
I know people who traded in the M8 for battery issues early on. I got mine after the updates hit, look at my numbers. And lots of M8 owners are posting great results also.
So I don't believe that there can be just one answer.
If the OP needs waterproof, the Samsung is better. If they want loud, clear speakers, the M8 is better. If they want to rely on the camera, then it's important to know the intended use. HTC optimized for fewer pixels and more compression and that's ideal for social media. Samsung optimized for more flexibility in cropping.
But if you care a whole lot about pictures, you can get far, far better than what comes out of the box for either one.
If you don't care about pictures, then you don't. I know people who carry cameras and don't care about tiny cell phone cameras.