OK I have some experience here so I'll offer my input.
I just bought a Dell Inspiron 8100. Wanted to get the internal WiFi, but for some reason if you do that they MAKE you buy a PC Card Ethernet/Modem combo @ $150 which is pointless for me, because I already have a 3Com combo card I wanted to use.
So I went ahead and ordered it with the internal built-in modem/ethernet, and ordered the WiFi internal card separately from their software and accessories store.
One thing that deserves pointing out. I think just about any "internal" modem/network card (wireless or wired) is not really built-in (as in soldered to the motherboard or anything). What it is is MiniPCI, which is a slot built into most newer laptops expressly for such a purpose. In the case of my Dell (the Inspiron 4000, 8000, and 8200 have it as well) it's easily accessible with one screw on the underside.
The WiFi MiniPCI card just came yesterday (cost about $80), and it came with everything I needed. The antenna is built into the screen of all the Inspiron models I just mentioned (whether it comes with the wireless card or not). So all I did was unscrew the panel, take out the 3Com combo modem/ethernet card already in there (it looks like a SODIMM, only a little wider), snap in the wireless card, and use the tiny little cable they included to attach the card to the notebook's internal antenna. Took about five minutes in total.
I expected to have to install drivers, but WinXP had them built in (God I love that). Plug and Play--boom... it was working like a champ.
Just for comparison's sake... I had an Orinoco Gold card previously, but personally I don't like how much it sticks out from the laptop. I have a port replicator/docking station for it, and the card makes it too wide to pass through the monitor stand, not to mention that I have to take the card out every time I put it in my laptop case.
I tried the 3Com XJack WiFi PC card, which is a great idea with it's retractible antenna. But of course there were no WinXP drivers for it for the longest time, and even after they released them I had tons of issues with it. Orinoco cards ARE the best (Well, the Cisco 350s are damn good too but expensive). They plug right in and work perfectly--no hassle.
What finally convinced me to go with the MiniPCI WiFi card from Dell is that I found out that it IS an Orinoco Gold. In fact, Agere is I think the only company that even makes WiFi cards in the MiniPCI form factor. That fact, plus the low price $80 for an Orinoco Gold is a steal won me over. Now I have my 3Com 56K modem/Ethernet PC card taking up a PC card slot (but its connector is XJack so no problems with anything sticking out). Plus I have one more PC card slot free for my GPS or a Compact Flash adapter (those are the only other PC cards I use).
I'm much better off having my wireless in the MiniPCI slot. I have a wireless network (Agere-based) both at work and at home, so I use it a lot. Plus, the port replicator for this is at work, so when I dock the notebook it uses the ethernet card built into the docking station. If I need to use an ethernet or modem connection when I'm away from home or the office I've got the PC card, which I can remove when not being used.
Not to mention that I've still got the 3Com MiniPCI modem/ethernet if I ever want to swap it back in.
And there are ways to flash the Dell MiniPCI with Orinoco firmware updates. I have downloaded the update but haven't installed it yet.
Also haven't tested range yet, but I will. So far the signal strength is reading as excellent, but admittedly that's only about 20 feet from the access point. I'll wander around the apartment and outside a bit later on and let you know how it goes.
If you end up getting a Dell, I say do what I did. It's only $80 extra, and then you have both options, and you can swap them in and out as you see fit. Or you could sell whichever one you don't use on fleabay and probably be out $0 when it's all said and done.
Whew! Hope that helps someone. I'm very pleased with the MiniPCI wireless... working great.
l2c