When OnePlus started, they were considerably cheaper than flagship phones from others. At $299, the OnePlus One was a ton less than the $650 you'd pay for an iPhone 6 or Galaxy S5. You were getting a 95% flagship phone at half the price. You could get a OnePlus One with the latest Qualcomm Snapdragon or you could get a Samsung with 30% the performance and a 640x480 low-res display for the same price.

I feel like the "something new" was price. Over time, that price kept creeping up. Yes, it went from being a 95% flagship to being a 100% flagship, but it also went from being half price to full price.

It was also cool that it used Cyanogenmod which meant you got a community OS that actually got updates, but over time other manufacturers started offering updates for their phones (rather than abandoning them soon after manufacturing). And that was something new other than price. But I think the big thing was that it was a half-price phone when it launched. In 2014, it was just such an amazing deal. Today, it's the same price as Samsung phones.

I bought many of the first models. They were good and very competitive with price and features. Custom ROMs everywhere. But I guess this is not so true anymore.

OnePlus was always a strange proposition to me. I remember debating it with colleagues when the hype started around their first phone. A lot of people and reviewers went crazy over the OnePlus phone, to me it seemed, and still does, as a pretty standard Android phone. The last review I saw was Linus Tech Tips reviewing the latest OnePlus, and Carl Pei commented that maybe Linus issue was that he was used to flagship phones and his expectations was a bit to high.

That really sums it up to me, then OnePlus phones are pretty standard Android phones, they are not really special, at least not to the extend where the brand means all that much to all but a minority of people.