Over the years I've had laptops from IBM, Toshiba, Compaq, HP, and Dell. For the most part I've been pretty lucky and not had many problems with any of them but I've also known people who have had a lot of problems with laptops from all of these vendors. As a general rule of thumb, if you buy a model targetted to the corporate market you seem to get a better product. Of course these are more expensive than the consumer grade models. In my experience, $2500 is not a lot of money for a laptop.
It sounds like you plan on using the laptop for a fair amount of work related activity. If this is the case you should enquire about having the company purchase the laptop rather than spending your own money.
Buying a laptop is completely different than buying a desktop system. With a desktop system, if you or someone you know has the right knowledge, you can build (or have built) a system which almost exactly meets your needs. In my last desktop system for example, I specified the make and model of every component, including things like the power supply. Unfortunately, with laptops you pretty much have to buy a preconfigured system and so you end up making a number of compromises.
I just recently went through the exercise of buying a new personal laptop (I like to keep my corporate and personal computing environments as separate as possible) and here are a few of the things to consider:
If you travel a lot the weight of the laptop and any necessary accessories is important, you don't want to be carrying 8-10lbs of computer gear if you can avoid it. If however you are only going to be carrying between your home/office and the car weight probably isn't a big consideration.
Battery life is also important if you fly much, you don't want to have a dead laptop halfway through your flight. For longer flights even the most energy conserving laptop will need two batteries. Some airlines are now providing power outlets (at least in business class) so this may not be as large a problem as in the past. If you are going to use a wireless network at work or home, you may find it convenient to run your laptop on battery fairly frequently (why give up the network cable but keep the power cable) so battery life would be important in this situation as well.
How powerful (CPU/memory) does the computer really need to be? If you are mainly going to use it to write reports, answer email, and make presentations (ie MS Office apps) then you can usually live with a less powerful computer. If you are planning on doing some significant calculations or software development then the more power the better.
You will find that it is virtually impossible to get a light, powerful laptop with a long battery life.
In terms of your network connections, I think you need to look into this further and I would suggest you discuss it with the IT staff in your workplace. Many companies do not allow non-corporate computers to be plugged into the corporate network for security reasons.
The most common form of wireless network is IEEE 802.11b (sometimes called WiFi) which is mostly used in offices and homes but has been deployed during the past year in a number of cafes, hotels and some airports. You will only be able to use this in areas where the appropriate infrastructure has been deployed and you have been provided with the necessary authorizations (if its deployed properly). Think of this technology as replacing the ethernet cable between your computer and the cable/dsl modem. Many vendors are building this type of wireless network into the laptops or offering it as an internal option.
If you really need connectivity "everywhere" then you might be thinking of the various offerings from the digital cellular phone services, often described as 2.5G or 3G services. In one of my previous positions I used such a service (although in a more primitive form) and found it adequate for solving critical problems through telnet sessions but would not have considered it useful for general activities such as surfing. Think of this technology as being a slow modem that you can use when you are on the go.
Neither of the two wireless technologies described above currently provide a viable alternative to a wired connection at home.
For travelling, I have found that most of the hotels I stay at now provide an optional (or in a few cases complimentary) high speed internet connection usually for about $10. Generally, I take advantage of this service and expense it. I've never had a problem expensing it but if I was ever questioned, it would be easy to jusitfy in terms the work that I was able to do by taking advantage of this service.
Gee, all that and I still managed not to answer your question.
