I am no laptop expert, but I have been assigned several in various consulting engagements and full time work and I really like the Vaios. For whatever reason, they have been very trouble free for me- no freezing up or anything like that.
Not a very technical reply I fear, but after 8 years of pond jumping and over 20 laptops to use, the 3 Vaios I had were the best. I never had a problem with any of them.
My bf works with and fixes computers as a part time job. He's advising me to get an IBM (my crappy dell just broke). He says that dells and toshibas use really shitty, cheap parts to get the costs down.