If you are going to be using your laptop for 12 to 18 hours a day, then you want a laptop designed for that purpose. The Presario, VAIO and most of the HP series are consumer models, what you want is a business laptop. Those are generally better engineered with higher quality parts which are made to run for longer periods of time, unlike the ones you are considering. The Lenovo Thinkpad line of laptops is, and has been for a very long time, one of the highest rated laptops manufactured. They have no equals on the corporate end and now with their consumer line of laptops they will be hard to beat there as well. If you check the reviews from pcmag and notebookreviews you will find the top rated laptops are from either Lenovo or Apple, and both are rate to the best tech support of any of the vendors around as well. Apple pros are that software is easier to install and uninstall then on any Windows machine. Apple cons software is more difficult to use. Sony pros, none that I can think of. Cons overpriced consumer equipment, not well suited for corporate environments. Lenovo pros, most reliable, best tech support, priced competitively, will take abuse, made to last. Lenovo cons, available in your choice of color as long as it is black (unless you purchase one of the consumer models). Dell Pros price. Dell, cons reliability as they are prone to catastrophic hardware failure, poor design and even poorer tech support. A little about my background, it is my job to evaluate and purchase hardware for my firm. We are replacing all of our equipment this year and are evaluating Lenovo, HP and Dell (preference is in order) and my budget is $22,000,000. Most vendors are component builders now, meaning that they purchase whatever happens to be the cheapest at the time. Lenovo will guarantee that you will have a consistent build across your order, making it easier to troubleshoot any problems and to image.