This palm strap is exactly what I was looking for. I have a Canon 550D with a 15-85 lens, which feels a bit front-heavy together. Also, walking around with the camera in your hand when your arm is stretched down felt a bit scary with just your finger tops over the camera grip; now it feels secure. The quality is perfect for the money, but the plastic part is a bit crooked. The flap with the logo is actually sewed on, from the pictures I thought it would open with velcrow. Material on the inside is rubbery material. hope it doesn't get sweaty in warmer countries.
With some fiddling, I managed to put the neck strap back on (only works after you put the palm strap on). I made the neck strap as short as possible for over my shoulder, so the camera can be 'hidden' securely between elbow and body. Works even if you have to run a bit.
Tip to make sure straps cannot slip: when putting the strap through the buckle, give the strap half a twist, right in the buckle.