Jeny:
Toshiba notebooks may be slightly more reliable than Dell but they are both major companies so you should choose the one you like best.
The critical thing is that if the 1.5 Pentium M is a 705 CPU and not a 715 CPU it is the older Banias Pentium M with 1mb L2 system cache.
The Dothan 1.6 Pentium M has 2mb L2 system cache -- this allows you to access web pages and other frequently accessed programs and screens much faster than using your RAM.
So, make sure you get a Dothan Pentium M no matter what you choose - you are fine if at 1.6 or above but the 1.5 has two cpus as I stated and Dell and HP are using the 705 1.5 to lower the price a bit but then you are getting screwed out of the new Dothan chip technology.
You really need to try the keyboard on both to decide. I like Toshiba better but you will have a 1 year limited warranty standard and similar components in the notebook either way (LCD is not even made by either company either -- made by Samsung, LG, Hitachi, etc).
Note that if you buy it on a gold or platinum credit card that offers the warranty doubling up to 1 year you can get an extra year of warranty for free from your credit card company (American Express and Citibank at least have this).