Since some days I'm also a lucky owner of a X1, so I can answer some questions.
There is one memory module slot, 256MB are soldered onboard. That's why the max is 1.28GB. What is a big plus of the X1 is the built-in Bluetooth module, whcih supports BT 2.0 with EDR. At the moment it's simply not possible to buy a USB stick with that features (will be may be better in some weeks).
Is BT also available for the X41?
And another point: the X41 looks heavier, and according to IBM's web site the weight is 3.3lbs (may be a different battery?)
The passive cooling seems to work - during heavy compile sessions the CPU reaches a temperature of 70 to 72C (read via ACPI from System - I have Gentoo Linux installed). Intel allows 100C. But anyway this is not a normal usage (and my dual Opteron is helping via distcc).
Another thing to mention: unlike some other notebooks the CF slot is not a USB connected card reader, it's a real PCMCIA slot in mini format, connected via a card bridge. If there is a need for PC cards in rare cases then a usage of a adapter is possible, at least for 3.3V cards. Ok, its not a nice mecahnical solution, but possible.
So far I really like this little device.
Sorry, this is my first notebook and I've not yet tried suspend. I spend some time to get distcc working, because my 64bit Gentoo box have to compile valid 32bit binaries for the X1. Now this is working.
According to http://freshrpms.net/docs/x1/ swsusp2 is working.
I just got my dell x1 a couple of days ago. A couple of comments:
The screen is really quite good. I also have a sony vaio tr1a with the xbrite screen and even though the dell has a matte finish, its just as bright as the sony. The viewing angle of the sony is better though. So its not quite as good as the sony, but its still very nice.
When I run super pi to 2million, I got 2 min 42 secs. Decent..
The dell uses the intel 915 graphics chip, just like the x41 so they are equivalent in that respect.
I debated between the ibm and the dell, but in the end the wide screen and higher resolution won me over.
How does the X1 seem durability wise? One thing I like about the Thinkpad series is the outside is very durable..it stands up great to normal wear and tear type activies. I don't have any experience with the X1 to get a feel for how easy it will scratch etc.
Spec wise the X1 is very tempting...the price Dell gave me for it is actually about the same as the X41 (taking into account a MC / Visa discout from IBM).
I am curious to see the full review...especially the speed comparison between the 1.1ghz in the X1 and the 1.5 in the X41.
Btw...Bluetooth is available on the X41 although it only comes installed on a few of the models. However, all X4x series ship with the anntenna installed in the machine allready (you can install an antenna yourself, however, it requires disassembly of almost the entire machine to run the wire) so it is quite easy to pop the keyboard off and exchange the modem card..the cost for the part is only about $60 from IBM. I think the BT on the X41 is version 1.1 (or 1.2?)
Does the heat bother anyone? Sounds like the laptop's internal components are ok with it, but as a human, the heat seems to get close to my threshold of comfort, and I don't know if some of my "cheap" table furniture laminates can withstand it...I know, prop it up with something. But if I am using my lap as a table (hence laptop), the heat can be very uncomfortable, especially on a hot short pants day!