Laptop Warranty Service, Asus, Acer, Dell, HP, Lenovo

Hi all..

I'm currently using a HP Pavilion M6 laptop..

I wanna know how HP is providing their warranty service and whether their service is good or not.

As I've read from several other topic, ASUS service really sucks.

Dell technician will come on site and repair the laptop if it's under warranty right?

How about Acer, and Lenovo?

Planning to get another laptop
Those touchscreen Windows 8 laptop is really tempting..

Please share with me your experience with the stated brand of laptop and many thanks