As an owner of a very similar SAMSUNG laptop, I can tell, if you want the best one at the cost of some time, get the SAMSUNG. The AMD A-Series APU will not work out-of-the-box with Ubuntu 11.10, however they do work pretty well with the lastest updates for 11.10, which you may achieve with a Minimal ISO. That or either using Ubuntu 12.04.
I would recommend using the lastest propietary drivers from AMD (I think they are actually 12.1), since the few ways I've found to make some heat on the laptop was either expensive gaming or using the open source drivers.
If that is not a problem, then go to the laptop as it is. SAMSUNG does provide a better build quality and materials. Also, design is more stylish. I love the fact that they use small bezels for screens since you get more space (a 15.6" laptop will look like a 14"). If you use your computer at anywhere except total darkness, you will get benefit of the matte-finish screen, compared with the glossy screens which will reflect every light.
Also, they use some BIOS-level battery technology, which if you enable, may charge the battery only up to 80%, that at cost of battery discharge time, it will let the battery a longer lifetime.
As for the ugly truth, I got difficult to get used to the fact that the keyboard does not have any CAPS LOCK light, but now I use a sound in Ubuntu to tell me so. One thing though, wrist-rest space is a fingerprint catcher. Back-cover too.
The laptop feels very solid, except on opening-closing the lid, which may require use of both hands most of the time. Speakers are somewhat weak compared to my brother's HP, still audio is pretty nice and clear.
Keep in mind, the SAMSUNG laptop is mostly aimed for business. Still, with proprietary drivers, the A8 APU with ATI HD6680G (I think), easily outperforms the Intel HD3000.
Also I don't know for the GATEWAY, but the SAMSUNG comes with Bluetooth 3.0.
Good luck, and if you need anymore info of SAMSUNG laptop, just tell me! ;)
Actually both will work in Ubuntu perfectly. I know this answer is very direct but is the truth with the hardware both have. The only recommendation i would have is to go with the one with the Intel video card. It is more friendly when you want to connect it to a TV for movies or to show someone what you are doing on the laptop.
That is about it. Both will work excellent.
While you should have no problems running Ubuntu on either of the machine, since you are asking for one choice, it will be the Gateway NV57H57U - vis-a-vis compatibility. The i5 with the HD 3000 graphics are a very very common configuration and things should work great out of the box (except perhaps the video tearing problem which can be fixed in under 30 seconds: Solution to tearing with HD 3000). Pretty much everything about the notebook seems to be the standard configuration, and you will have no issues. This is not to say that I am aware of any problems with AMD Radeon Graphics and Ubuntu. It is just that the other option is widely used and tested.
both must be work very well with you choose anyone
but if you need my opinion choose Gateway
because it's very better than samsung it's have intel core i5 very good , hard disk in samsung is very good because it's black but blue well good will good with core i5
and finally like all said for you both well good with ubuntu
I think Gateway NV57H57U is more friendly then Samsung for Ubuntu.
I am having a huge heating problem on running Ubuntu in my Toshiba laptop. I will like to suggest to get Dell XPS with Ubuntu installed. OR the system76 laptop also works fine for running Ubuntu.
Beside this many laptops of Dell and HP supports Ubuntu and most of them comes with Ubuntu pre-installed.