Well, Samsung's major issues have been lack of updates for their phones...but among other reasons, that's probably mainly due to their custom UI combined with whatever carrier issues there are...not sure. But running pure Gingerbread, updates should come first to this phone from Google. Plus...since it already has Gingerbread, you wont be needing an update for a long time anyway. Plus there are the thoughts that Honeycomb will require dual core anyway so updates may not really be an issue....but who knows.
I just dislike Samsung phone styling and build quality in general. Below is taken from the AC review of the Nexus S....all disappointing, and don't make up for the screen in my opinion:
What we didn't like about the hardware
Lack of a notification light -- it's inexcusable to release any phone without one. Even if you don't depend on it, many other users do, and should be provided one. Software solutions just aren't the same, no matter how well they are done.
No external storage -- Yes, streaming from the cloud is the future, and Google is all about the cloud, but not including a swapable microSD card seems like a step backward. The boost in speed that comes with having your apps store data on the internal storage instead of an SD card is nice (Need for Speed Shift is phenomenal on this thing), and 16 GB is probably more than enough for the average user. But don't tout a feature (moving apps to the SD card was officially added in Android 2.2. Froyo), then take it away with a hardware change.
No 4G -- The Nexus S supports T-Mobile's HSPA data speeds up to 7 Mb/s. That's fast, but wouldn't support for 14.4 Mb/s be better? I'll likely never see those speeds in my neck of the woods, but lots of other people do, and would be more interested. Nobody is really sure why it was done, but I imagine there had to be a reason, it's too big to be an accident.
No trackball or optical pad -- OK, this one's pretty subjective, and with the new keyboard that comes with Gingerbread, maybe even unneeded. But I wish it had one, because they are pretty handy if you're used to having one.
The camera -- Yes, 720p video recording would be nice, and with the last generation of phones supporting it, we really expected it. Maybe we will see that in an update, maybe not, but it's not the only issue here. Stills come out OK, as long as you have enough light and hold the phone steady.
Source: Samsung Nexus S review | Android Central
EDIT: To be fair, the review was ended saying:
"I think the Nexus S is the best Android device made to date. It's faster than any other phone available, and I've tried them side by side. When you take Samsung's excellent Hummingbird system-on-a-chip and the very nice Super AMOLED screen, then build the rest of the hardware, firmware, and OS to Google's specs you have the phone many of us have been waiting for."
...I actually missed that paragraph the first time I read the review....and it makes no sense since the review seemed to list so many disappointments.. calling it the "best Android device made to date" doesn't make much sense to me.
"The shell of the phone screams Samsung, and that's one of my biggest gripes about the Nexus S. If you love shiny, hard plastic, you'll disagree. There's nothing inherently wrong with the materials, but they lack the sophistication and little touches that set other Android phones apart. You'll find no soft-touch coating, or textured surfaces anywhere." -- yet in the conclusion, the hardware build is listed as one of the reasons it is the best Android device.
I'm not trying to tear the review apart...it just doesn't seem to come together for me, so I'm not sure what side I would take since I haven't experienced the phone. I think the decision to call it the best was based solely on: how easy it is to hack, and Gingerbread.