The GT 130m has only been recently offered on the HDX line - the 9600 was the standard card previously, so there really isn't much feedback on how well it'll perform in the field. However, what you might not know about 64 bit systems is that they use both system and GPU RAM for the entire system.
The HDX was only recently offered with an upgrade to 8gb - if the overall cost is less than $320 to upgrade, then do it now rather than later. Upgrade modules for 64 bit systems are getting harder to find - several of us who own the 20" HDX had to get them shipped from Australia. Unbelievable though for the programs that use it.
The HDX 18 is the "downgrade" solution from HP to the size of the 20" Dragon, which was discontinued last fall, but which now continues in high demand, if you can find a new or refurbed unit. The HDX 18 is also about half the weight of the Dragon, and while only a bit smaller, the lighter weight makes it much easier to carry. The Dragon is not for the weak - at 16lbs, once you put the adapter and battery into a case you're looking at 20lbs easy. But since I don't really take mine anywhere that often I don't worry about it.
I have one friend who owns a 20" HDX and is a Graphics Design student at American University down in D.C. Like most of us, he loves his, despite the size. The problem with most people is they want small and light, but for of use who are engineers, techs, designers, etc., we want bigger, especially for playing BD movies or Video Production. Who wants to watch a BD movie on a dinky notebook screen? 1080p all the way, in full 20.1" HD. Or for you, 18".
Considering I paid just over $4,000 for my Dragon (I've got every upgrade option possible) and used an HP Employee Discount, $2700 isn't bad, though it's not the top configuration. The only option I'd probably get myself is the new Blu-Ray Burner option, which just started being offered on the 18 within the past month. Though we often say we'll upgrade later, it's easier to just do it up front.
Cases - HP offers a Targus Rollercase that will easily fit the 20" Dragon, so it'll take yours as well. It can be used as a roller, carry, or backpack. For a traditional case, most either get the Dicota Multigiant or something not made specifically for computers. There aren't many options for cases in anything over 17".
Accessories - Don't buy any Extended Support, docks, etc. yet - you'll get a lot of coupons to use at the HP Online store with your system.
Since I spend a lot of time on the HP Forums, I can tell you one thing about the HDX line that has been fairly consistent - when it comes to constant problems, there aren't any. There was a problem with some of the 20" Dragons updating to the F.40 BIOS, but to my knowledge that hasn't been an issue for the newer 18's and 16's.
You might want to check through the HDX-18 Owner's Lounge also. When they came out, we asked NBR to split the HDX community, since frankly, the 18's and 16's just aren't the same as a Dragon. But I'd pick an 18 over a 16 if that were my only choices in a heartbeat.
People tend to put to much emphasis on a system's GPU when talking about gaming also. A lot of problems many attribute to GPU performance is actually bad networking setup. The average gamer doesn't know much about setting up a network for online gaming, which is crucial if you want to be in the top percentage of players, or be one of the bullet sponges for the rest of us with top-speed networks. People will shell out a lot for a top performance system, but spend nothing on their networks. Even the fastest racehorse is slow when running in mud. One of the problems I've noticed recently with the Intel adapters is that they can be set up individually to match router settings for better performance, but most aren't doing it and having issues as a result.
With an 8gb 64 bit system, you shouldn't have any problems gaming online, but check the specs for the specific games you play to be sure. And again, if your network is crap, it won't make any difference anyway.
Battery charge - depends completely on your Power Plan setup, but most will get at least an hour or more. For the HDX's, the screen is the biggest power hog, so I cut my monitor levels down quite a bit when on battery. If you're curious though, you can look at this:
How to Improve the Performance of the Battery
I'm not sure if they still offer it on the 18, but for the Dragon HP offered Lojacking at the BIOS level, which can only be done during assembly and configuration. It doesn't run that much more if offered, but it's something you can't get afterward.
Problems? See this thread at archive.org.
