The Galaxy S5, inspite of all the badmouthing that it takes, is an awesome phone.
Yes, it doesnt flaunt brushed aluminium, or glass panels, but how many of us use our phones without a back cover?
Coming to the pros:
1) Awesome awesome screen: AMOLED makes a big difference. People might crib saying that 432 ppi is less that 441ppi of other flagships. But hey, does it make a discernible difference? Anything above 400 ppi looks the same. What you get here are the amazing punchy colours and stellar sunlight visibility.
2) Camera: I own a Nikon D5000 DSLR, an have done a thorough comparison between the two. In good light, I dare say that the S5s pictures have more detail and better colours. In short, the S5 has one of the best(if not the best) smartphone camera today. Megapixels is only a way to fool the ignorant consumer. It is sensor dynamic range, and low light performance which makes a difference in the real world.
3) Size: This might be a personal thingy. But in my opinion, and having used a phablet before, I think that anything above 5 inches retards its usability. The S5 is thin, light, highly pocketable, and build upto flagship standards.
4) Apps: Some software features are really cool, and enhance the usability. I personally use the feature S Health, and I find it great.
However, it has the following Cons:
1) Looks and Build: Yes, metal or glass is actually more premium. The chrome finish lining around the frame looks cheap. However, I liked its leather finish back.
2) Bit laggy: Compared to an iphone, or even an Xperia Z2, the S5 experiences more lag. Might be due to excessive bloatware. 3GB RAM would have been better.
3) Battery Life: I am not complaining here, but yeh dil maange more.:P
All in all, the S5 is a sweet phone. The best all rounder, and definitely an owners pride.