I have no experience with the "Touch Smart" PCs, however:
HP makes two different major lines of PCs, one for home users, one for business use. The home series includes many of the Compaq models and all the Pavillion models, including the Touch Screen models. The home series (like Dell and others) is built to an extremely tight price point (read this as lots of price competition, especially on the lower end models - meaning that components are sourced with price as a high weighting factor.)
The HP Business line of PCs is geherally built better, since many businesses get past the "cheapest up front" and move on to the "cheapest in the long run" philosophy. My company owns about 20 computers, all the desktops, workstations, and servers are HP, the notebooks are a mix of Compaq and Lenovo (IBM ThinkPad). I don't sell computers, but earn billable hours helping my clients purchase what will best meet their needs, and I do send a lot of them to
www.hp.com for their purchases.
In general, the only clients that I would specifically recommend any Touch Screen computer to are those who need to run custom applications designed to work with Touch Screens (like restaurants) where a limited number of inputs are chosen, the keyboard is not used (or used very little), and the touch screen's additional cost is needed for egronomic factors (dentist office, etc.) I do use one Touch Screen device, the BlackBerry Storm 2 - perfect for the application of carrying it everywhere - reduces the number of places where dirt and grime can get into the machine.
Summary: If you buy at the higher end, I can recommend HP without hesitation. I bought a group of the high-end PC workstations, they have been very reliable - NO failures except a couple of hard drives and one power supply that developed a noisy fan (still worked, but noisy) in a 7 year period.