Height and width are nearly identical, but the OnePlus 3 comes out 25 percent thinner.
The new model is also 10 percent lighter.
The OnePlus 3 goes with what's now more or less the industry standard among flagships, an aluminum unibody design.
Last year's model had an aluminum and magnesium frame, but with interchangeable backs. It ships with a standard plastic one, but there are also bamboo, apricot, rosewood and kevlar options to choose from.
There's a similar setup for the OnePlus 3, but instead of new backs for the phone, they're protective cases made out of (some of) the same materials (plus "Karbon" and sandstone, and minus the kevlar).
The OnePlus 3 currently only ships in gray, though there's going to be a gold model at some point as well.
Last year's model shipped with that default black backing, though the replacements added two brown-ish colors and a couple of black-ish options.
No changes here, as OnePlus stuck with a spacious 5.5-inch display.
OnePlus switched from IPS to AMOLED with the new model.
Thanks to that AMOLED display, there's an option in the OnePlus 3 to have an always-on display, where time, date and other info show on an otherwise black screen.
The Snapdragon 810 still holds up well today, but we find 820 phones to be noticeably zippier. It also benchmarks quite a bit higher.
OnePlus went with an insane 6 GB of RAM in the 3. The OnePlus 2 originally shipped in 3 GB and 4 GB variants (tied to storage tiers), but it looks like the company now only sells the 4 GB model.
If you're buying either phone right now, then 64 GB is your only storage option, as OnePlus appears to have phased out that 16 GB storage/3 GB RAM version of the 2.
It's a good thing you get all that internal storage, because there's no expansion here.
Curiously, OnePlus left NFC out of last year's model – a questionable call, since mobile payments were starting to catch on right around then. The new model remedies that, and supports Android Pay.
The newer model has a slightly smaller battery, but that won't necessarily translate into shorter battery life. Stay tuned for our review for battery impressions.
Another missing piece from the OnePlus 2 was put in place with the "Dash Charge" feature in the OnePlus 3.
There's still no wireless charging, though, on either handset.
Both cameras get a resolution bump; this is another one to watch out for in our review.
Camera aperture (rear)
No aperture change, though, could potentially mean low-lit photography doesn't drastically improve.
Optical Image Stabilization is still around for 2016.
No surprises here, as both phones have fingerprint sensors below their screens.
There's no water resistance on either OnePlus phone.
The OnePlus 2 was the first big flagship to go with USB-C, and the new model sticks with the reversible standard.
For a phone that runs a near stock version of Android, it took OnePlus an unusually long time to roll out the Marshmallow update to the OnePlus 2. It was stuck on Lollipop until about a month ago, eight months after Google pushed Marshmallow out to Nexus devices.
You might want to keep this in mind if you buy the OnePlus 3. Its software may look Nexus-like, but don't expect a Nexus-like turnaround after Android Nougat launches.
The OnePlus 3 has been available since last month, and fortunately the company ditched its annoying invite system this time around. You can finally go online, order the phone and get it a few days later – no more gimmicks.
Starting price (full retail)
If you don't own either phone and you can afford that extra US$100, the OnePlus 3 is a faster, lighter and thinner phone with a higher-end design and a few other perks.
For more, you can check out our full review of the OnePlus 3.
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