Let me start off by saying this is not my first Galaxy. I started with the Galaxy S4 the day it came out after being a longtime Apple user. I switched at the time I felt Android was on par with iOS and since then I believe it's been iOS that's been playing catchup with Android. I then upgraded to the Galaxy S5 and now the S6. I picked this phone up on Friday the day it was released.
Physical: The phone itself is a thing of beauty. Yes, it looks like an iPhone 6, but so what? The iPhone 6 is a very well made device. From a distance, you might be fooled but get up close and there's no doubt, this thing has the look of a Galaxy. Gone are the ugly plastic dimples on the back of the S5, replaced by smooth glass. I love the way the glass front and back smoothly transition into the metal frame. As a Galaxy S5 user I am happy to see that the charging cover flap is gone. Unfortunately, waterproofing is also gone. It was nice to take the previous generation into the lazy river of a water park but honestly I'm happy to give up waterproofing for such beautiful aesthetics. The power button has been moved about a half inch from the S5, almost to the center of the right side of the phone. It's going to take me a while to get used to that. The metal frame on either side has a straight bevel that really helps in holding the phone. The home button is slightly larger to accommodate the new touch fingerprint which works much better than the previous versions swipe fingerprint sensor.
Storage: Yes, the microSD expansion is gone. Is this is a bad thing? For some, maybe. Most users are probably fine without it. I had microSD cards popped into my previous phones and tablets so I thought I would miss this feature. In reality, the microSD functionality on Android is limited, so I hardly used it. Most apps like large games can't be installed onto the SD card. My movies and music are in the cloud. About the only thing it was useful for was storing photos, as it was really easy to move them to the next phone. But really, those are backed up to the cloud too. Point is, the way we manage our data has dramatically changed since expansion storage was introduced and with the generous onboard storage this phone gives you I don't think it's needed anymore.
Battery: The battery is smaller than the S5 and non-removable. To me the fact that it's non-removable is not an issue. Is the battery life shorter? Too early to tell. The fact that I can just set my phone down on a pad and watch it charge is amazing though. Another feature (like wireless payments) that Android beat Apple to. I haven't had a chance to test the quick charging feature. So far the battery does not feel to drain any faster than I would expect.
Performance: One of the first things I noticed in the first hour of using this thing is how fast it is. It really flies compares to the S5. And my S5 was recently restored to factory so it's a fair comparison. I think Samsung made the right decision going with their in-house Exynos processors instead of the Snapdragon this time around. I have confidence this thing will run anything you throw at it.
Software: It's Android 5.0.2 with the typical Samsung spin on it, known as TouchWiz. In the past Samsung would throw every bell and whistle they could into their software offerings to try to differentiate itself. In this latest version only the best of those features remain like multiwindow, power saving, S-health, etc. The Do Not Disturb mode finally works properly. The UI itself finally looks polished and well blended with the underlying Android UI. The settings menu is better organized.
Bloatware: Yes, depending on the carrier, the phone comes with a lot of apps you probably don't want. But guess what Apple fans? iOS has bloatware too and you can't remove it. I don't want apps like Apple Watch, Passbook, Newstand, Stocks, Weather, etc on my phone. HIding them in a folder is not acceptable to me. The S6 allows you to disable all of the default apps so that they are no longer consuming cpu, memory, or space in your app drawer. Remember that default applications are system apps so the fact that you can't actually delete them is a non-issue. They are on a system partition so deleting them would not provide you with any more usable space.
Camera: I am most impressed by the camera on this phone. It is very fast - just tap the home button twice to open the camera app. You no longer need a camera icon on your home page to launch the camera. Low light pictures are some of the best I've seen on a smartphone. I will probably not be using my DSLR as much as I have been. This thing also takes 4K video (again...sorry Apple fans) which looks absolutely stunning on my 4k monitor.
Overall, I would recommend this phone to anyone - even diehard Apple fans.