They both look like nice laptops for $500. I'm pretty sure you could say "overheating issues in the past" about any laptop dealer. It depends more on the cpu and/or graphics chipset for overheating than the brand of laptop.
Typically you can expect toshiba to make nice laptops for business. The specs are so close here though that I think you should consider two things:
Which one has a better screen? This is where most manufacturers skimp on budget laptops.
Which one is more aesthetically pleasing and nicest keyboard? If you're spending $500 it should be comfortable.
Personally I would check PCWorld.com. They test ALOT of laptops and have thorough reviews available in all price ranges.