These all seem to be fairly standard consumer grade pc's not normally my forte(business laptops normally for me w510 thinkpad currently) due to prefrence and their general projected lifespans however the decision here seems clear on the msi for 2 reasons.
1. Hp is looking to close their pc division any future support is uncertain.
2. The asus is out of stock assuming you intend to order from newegg that leaves only the msi.
I would like to throw this in for your consideration as an alternative however, normally i use thinkpads this is the consumer equivelent.http://outlet.lenovo.com/laptops/ideapad/439525u.html
Edit: there were 4 of that machine in stock when i orginally wrote that post and are now 0(i went to show it to a friend of mine) the only other laptop i would reccomend is 1200 dollars and is probably far our of budget in place of the 730 dollar msi