I've spent most of my time recently working on two or three of my new (or not so) sub-netbook systems, with surprising results. This information might be useful to others who are looking at such systems:
HP Pavilion dm1-4010ez: This is the newest of the lot, and it really is a very nice system. It loaded and ran flawlessly with every Linux distribution I tried on it, including openSuSE 12.1, Fedora 16, Linux Mint 12 (with Cinnamon), Ubuntu 11.10, Linux Mint Debian 2101109 Gnome, PCLinuxOS 2011.09 and probably one or two others that slip my mind right now. It really was a pleasure to use - so much so that a friend who needed a replacement for a very old ASUS netbook I had set up several years ago ended up taking this one from me. Ah well...
HP Pavilion dm1-3105ez: This is the oldest of the lot, I've had it for about a year now, and it has always been a bit of an anomaly. I hate using it because of the blasted Synaptics ClickPad monstrosity, but as soon as I put an external mouse or trackball on it I love using it because in every other way it is a wonderful system. The one other quirk about it, a Ralink 5390 WiFi adapter, has long since become a non-issue because the driver for it is included in Linux kernel 3.0 and higher. I have it loaded with all of the distributions listed above, and they all work great. But then I got myself into trouble with it. I wanted to replace my partner's Samsung N150 Plus, mostly because of the very irritating display brightness fluctuation problem with some distributions. So I decided to give her the dm1-3105 - she can use it with Windows or openSuSE, both have good support for that blasted touchpad and do not have the display brightness problem. She gets a much nicer, much newer and much faster system with a larger display, and I still have it around to keep an eye on how support for the ClickPad develops in future Linux releases. Except things didn't quite work out that way. The ClickPad turns out to be such a nightmare, even under Windows, that she struggled with it from the very beginning. After watching her suffer for a couple of days, I just couldn't stand it any longer, so now I have this one back, and I'm still using it with an external mouse/trackball and hoping for better ClickPad support in the future. Sigh.
Samsung 305U: This is the one which I was going to send back for repair or replacement. Except a funny thing happened along the way. I had it all ready to go, even with a mailing label ready to stick on the box, when I decided to write up some very specific instructions for the repair center on how to reproduce the two major problems when running Windows (no one in those places is interested in hearing about Linux problems). First up, the screen flickering after coming back from screen-blanking. Easy enough, just boot up, let it sit idle for a few minutes until the screen goes blank, and then touch a key. Except, it didn't flicker. Solid as a rock. I tried several times, several ways, with external power and on battery power, and it never flickered. I was SURE that I had seen it flicker under Windows, but then I realized that what must have happened was that it started flickering under Linux, and then I rebooted to check it with Windows - but without powering off/on. Nothing I could do got it to start flickering under Windows. So I booted whatever version of Linux I still had on, left it idle until the screen blanked, touched a key, and WHAM, the flickering started. Grrr. Okay, so I can't report this one to the repair center. But the other one, the WiFi signal strength and throughput, that is more serious anyway. Except, when I tested that with Windows, it wasn't very bad at all. To be perfectly honest, it does tend to show a slightly lower signal strength than either the N150 Plus or my Samsung NF310 when placed in the same location, but it still works, and throughput is reasonable. Specific cases of WiFi signal strength and throughput vary so much from one system to another that it really has to be a very serious case before you'll get any sympathy from a manufacturer/distributor. I went all over the house, from right beside the router to the furthest point in the living room two floors below, and everywhere that the other two systems would connect, the 305U would also connect. So no way to send that back on the basis of the WiFi either. Bleah.
Now I have very mixed feelings about the 305U. On one hand I have said since the first time I opened the box that I thought it was a wonderful system. The whole time that I was testing it with Linux, and it was failing, I kept thinking "wow, I wish this would work because I REALLY like this thing". Now it turns out that the "fault", if you want to call it that, lies with Linux. Something has obviously changed with the Broadcom 4313 WiFi adapter, or around that adapter, and Linux is not handling it correctly. This is very strange, because I have at least three or four other systems which appear to have the same adapter, and they work perfectly. But, the driver for this (brcmsmac) is the one which was recently open-sourced by Broadcom, and there were a few comments about it still having "rough spots" in it not long ago, so maybe it's something to do with that. Or maybe something in the hardware really has changed, it's a new generation of the chip or some such. Whatever it is, I expect this will be fixed in the near future, as has been the case with every other significant device/driver problem I have run into (except that stupid ClickPad). As for the other problem, screen flickering on a Samsung system with Linux? Hello? Jamie, are you there? Read the first paragraph above... the specific kind of "flickering" is different, but gosh, problems with screen brightness on Samsung systems shouldn't be a big surprise, should it? The short term solution is simple, the same as for the others - just change the power settings so that the screen doesn't blank! The medium term solution is not much more difficult - I booted up Linux Mint 12 and told it to install the proprietary ATI flgrx driver. Rebooted after installation, test again and the flickering is gone. So this is apparently a problem with the FOSS Radeon driver. The long term solution, as with the WiFi problem, is that if this is a general problem with the Radeon driver and the latest Radeon graphic controllers, the driver will be fixed sometime in the near future.
So, for the time being I have taken back the HP from my partner, and given her the 305U. She likes it every bit as much as I did, and she is not bothered by using it under Windows until the Linux problems get sorted out. It seems to be working just fine for her, so we are all happy for the time being, and I can still hope that in the future I will be able to reclaim the 305U. (Not likely, to be honest, because she is not likely to be willing to give it up...).