If you search this or any other Windows 7 related forums, you can read that the majority thinks you are crazy if you even think about in-place upgrade. What you can not read is that most of these people have never tried it themselves. It's like an urban myth, waiting the Mythbusters to declare it busted: "My mate had heard that somebody had read that an in-place always fails".
Personally, because of my work, I've done tens, maybe hundreds of in-place upgrade installations from Win95 to Win98, from Win98 to Win2000, from Win2000 to Win XP, from XP to Vista and lately from Vista to Win7. I have never failed to get an upgraded computer to work. I do not know why. Maybe because I understand upgrading an operating system is like anything else in computing: if you prepare and do it right it's going to work, if you don't want to read every dialog on your screen and don't prepare, it's going to fail.
I've made a short checklist to in-place upgraders, you can read it
here. However, I have to say if the amount of personal files and applications needed to reinstall is not too big, please do a clean install. An in-place upgrade always works if done right and prepared, but it takes easily a lot longer than doing a clean install, reinstalling software and transferring personal files.
One more thing: HP's QuickLaunch is maybe the most problematic of all HP software, it still has several issues with Win7. I have a few HDX and Pavilion series laptops and I have intentionally uninstalled HP QuickLaunch Buttons from each and every machine.
Whatever you decide, clean or in-place, come back with your issues and questions. You are going to see some answers here to your question telling something like "Only fool does an in-place upgrade" etc. I know I am considered as an unofficial village idiot because of my opinion about in-place upgrade.
I leave it to you to decide. Good luck, whatever you decide.
Kari