My iPhone 4 needs to be replaced. I tried to accomplish the task with a Lumia 800, but as you can read in my review, it didn't go as hoped. Since I am a Telus employee/customer the contenders for my next device include: the HTC One S and the Samsung Galaxy Nexus.
As I see it the strengths of the HTC are the camera and the build quality, but it falls short in the qHD PenTile display, and Sense 4 (even if it is greatly improved).
The Galaxy Nexus has the 720p display, and stock Android. The build quality is 'Samsungy' and the camera a little lackluster. However, from my understanding the Nexus camera is on-par with the iPhone 4, and I am quite okay with that.
I would appreciate any ideas as to which device I should choose.
Play with them in a shop for 20 mins. I did with the One X and G Nex. Despite the One X's better build, far superior camera, and slightly better screen, I went the G Nex. Vanilla ICS was just so much nicer than HTC Sense (IMHO). I was coming from a HTC Desire and just had to have pure Google. No regrets so far.
How do you feel about size? The One S has a 4.3" screen and the Nexus has a 4.65" screen. The Nexus comes in a tad larger than the One S. While it doesn't sound like much, you are coming from an iPhone so the One S is already a jump in size.
On the camera, I can't say if the Nexus is on par with the iPhone 4, but I do know it is the most negative thing talked about on the phone and then battery life coming in second. I'm not sure about the battery life on the One S.
I have very large hands, so size isn't an issue. I gather that the Nexus is on par with the 4, because it has the same module as the Nexus S. Myriam Joire at Engadget said that the two are on par. She also said that the GSM Nexus' battery life is exponentially better than the Verizon model.
It's a tough call if you really don't want your iPhone 4 anymore, but I can say for sure that the Galaxy Nexus / Nexus S camera is not nearly as good as the iPhone 4. I suspect the One S camera is at least noticeably better than the Galaxy Nexus.