T40 for $500... a good investment?

Here I am again with a question--I hope I'm not getting annoying yet.

I'm curious to get some opinions on the T40. I know it's a bit old now, but I'm looking at a deal right now where I can get a T40 ("lightly used" not refurbished) for about $500 US (including shipping)... specs are:

Pentium M @ 1.6 GHz
1GB RAM
60GB HDD

etc.

My computing needs are relatively minimal. I need a notebook that is relatively portable and energy efficient (long battery life), with which I can connect wirelessly to the internet, do word processing, spreadsheets etc. I also need a machine that will last me a while (say 4-5 years) and accomplish these tasks well in that time frame. With this in mind:

1. How does the Pentium M stack up against in core duo in terms of energy efficiency? (i.e. would it be dumb to buy a Pentium M now given that the new awesome core duo is out?)
2. Should I be concerned that the built-in wireless on the T40 supports only the wireless "b" format?
3. Is the 1.6 GHz M-class processor sufficient for my computing needs? I think that it probably is, especially given that I get 1 GB of system memory, but I'm curious to know from someone who's used one of these machines, especially given that WinXP can be such a hog sometimes... (fortunately, I suspect that the apps I will run don't take a lot of processing power).
4. The main reasons that I'm interested in a ThinkPad are the fact that I love the solid construction, awesome keyboard, and trackpoint. Am I correct in thinking that these features are fully present in the T40?
5. Finally, I'm not at all interested in upgrading to Vista, so don't concern yourself with that in answering my questions.

 

1) Core Duo will yield about 50% greater performance. Energy use, slighly more drain on the battery as far as I know.
2) Depends on what 'frequency' you will be using wireless. Find out if the locations support b, and not only a/g.
3)Yes.
4)Yes, you are correct.
5)Okay.

 

Wireless A is the oddball one. basically all Wifi setups support at least b. b and g operate on the same frequency, so unless the AP has B turned off (unlikely in a public access type situation), you'll be fine with only b.
I know there is a 9 cell battery option for the T40, which will probably give you ~4 hours of usage with Wifi on and the screen brightness at about half.
Given your requirements, a T40 would be more than perfect. before it died, I was doing word processing with my old X21 and it had all the power I needed for that.

 

Core duo is huge overkill for word processing, spreadsheets, browsing.
I have both core duo thinkpad and a 1.6 ghz pentium M thinkpads (one with 1-gig and another with 512mb)

The T40 runs those apps fine even with 512mb on win xp pro.

You only need 512mb, but you can upgrade to 1gig for $50 or less. You'll be happy with your performance. As for your wireless, you can upgrade that too to a g-card, and get a decent router. Core duo won't help your wireless connections one bit.

Instead, spend your money on a new battery, more RAM, a good router, maybe a bluetooth mouse or printer or peripherals you'd like.

 

For basics tasks, the Core Duo won't be hugely faster.