Well based on my experience, they are pretty good! Just had the 3rd Toshiba Satellites (different models) in the house. Two of them are working, no problems, but the first one we bought is temporarily defective. Its hard drive broke, but its old! (Also, Hard Drives are usually one of the first things that break) 3 years old now and we weren't that careful with it and was dropped couple of times. Its simple to replace the hard drive anyways.
To be honest I like the excellent build quality of Toshiba laptops. However, I do like to note that I have experienced some freezing after installing some updates. This does not mean the Toshiba is not reliable, all laptops freeze at some point. So far, mine has no problems except that freezing at start up (happened only twice), and again, not all of them are like this. That was maybe the cause of a bad update or some other factors. Im using it as I type this write now. Its such a beast. The keyboard is so good, excellent Dolby Advance harman/kardon speakers, the LCD screen is crisp, quick boot up..etc.
My specs:
Toshiba Satellite P750
intel core i7-2630qm (QUAD CORE!!!)
4 GB RAM
1 GB Nvidia gt 540m
750 GB HARD DRIVE!!!
To specifically answer your question:
Pros:
Highly Durable
Reliable
Excellent Build
Good ventilation
Good LCD/Speakers
Cons:
In my opinion, what differentiates laptops from each other is mainly NOT the brand, but its BUILD quality. Laptops have lifespans of usually 3-5 years, depending on how you take care of it and the quality of its parts/materials. A good ventilation is also a must-have for laptops to prevent overheating thus increasing the wear and tear of the machine.
In saying that, most people find the Japanese brands Toshiba and Sony to be most reliable brands/builds in the market.
Mind you, we had a local branded laptop awhile back, it lasted almost 4 years! Nothing broke within the time frame..so..i guess its how you take care of it. All the best with your laptop buying decision!
I love Toshiba!