Yes, I've also had continuing issues with the fingerprint sensor on my S7. It's a step up from the swipe style of the Note 4, but it's nowhere nearly as accurate as the one on my Nexus 6P... the 6P gets it right 95%+ while my S7 struggles to get a 50-60% first-try unlock rate. There are suggestions that people have come up with that can kind of help, apparently. When registering the fingerprint it helps to move your fingertip around some and trying to capture every part of it. It also apparently helps if you use multiple fingerprint slots for one finger, but because of the sensor's location at the front of the phone I personally want to use four different fingers so I can unlock from a variety of situations (two thumbs for when I'm holding the phone, two index fingers for when it's lying on a flat surface). Kind of stupid for them to only allow 4 slots, but whatever.
The best tip I can give that seems to improve the success rate is to use almost no pressure when holding your fingerprint to the sensor. Since the S7 needs to be woken up before it'll unlock using the sensor, I find that I typically end up pressing the home button to wake the phone. The force required to press the home button seems like it kind of smushes the fingerprints and causes it to fail to unlock. Pressing the home button to wake the phone, then lifting the finger to let the screen turn on, then very very lightly touching my fingerprint to the sensor seems to work with a slightly higher success rate.